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SUBNORMAL  SCHOOL, 

kOS  HflCSUHS,  emu. 


UNIVERSITY  of  CALIFORNIA 

AT 

LOS  ANGELES 

LIBRARY 


FIRST    PRINCIPLES 


OF 


AGRICULTURE. 


BT 


EDWARD  B.  VOORHEES,  A.M. 

Director  of  the  New  Jersey  Agricultural  Experiment  Station, 

and  Professor  of  Agriculture  in  Rutgers  College, 

New  Brunswick,  N.J. 


/  8^3J 


SILVER,  BURDETT  AND  COMPANY. 
New  York.    BOSTON.     Chicago. 


I8C^ 


COPTBIGHT,  1805, 
BT  SlLVBB,  BUBDETT  AND  COMPAH« 


6^35 
Vg9-f 


PREFACE. 


The  purpose  of  this  book  is  to  state  in  logical  order 
the  elementary  principles  of  scientific  agriculture,  and 
to  show  the  relation  of  these  scientific  facts  to  farm 
practice.  The  need  of  such  a  book  has  been  strongly- 
felt  by  the  author  in  his  work  as  a  teacher,  not  only  of 
college  students,  but  of  those  already  engaged  in  farming. 

His  experience,  both  as  a  practical  farmer  and  as  a 
teacher  of  the  theory  and  application  of  agricultural 
science,  leads  him  to  believe  that  the  principles  and 
relations  of  scientific  agriculture,  if  set  forth  clearly  and 
in  a  scientific  manner,  can  be  successfully  taught  in  our 
country  district  schools.  It  is  here  that  such  education 
must  begin,  if  it  is  to  reach  and  influence  the  mass  of 
farmers,  upon  whom  rests  the  chief  burden  of  irrational 
practice,  and  through  whom  must  come  any  direct  pro- 
gress in  the  true  development  of  the  farming  industry. 

In  the  preparation  of  the  book  no  attempt  has  been 
made  to  cover  the  whole  field  of  the  various  sciences 
in  their  relations  to  agriculture ;  in  many  branches,  only 
simple  facts  are  stated,  though  it  has  been  the  aim  to 
make  the  book  scientific  as  far  as  it  goes,  and  thus  a 
safe  guide  to  practical  men  in  their  farming  operations, 
as  well  as  a  foundation  upon  which  further  study  may 
be  based. 

3 


4  PREFACE. 

The  accomplishment  of  the  work  is  due  in  no  small 
degree  to  the  endorsement  of  the  plan  by  the  New  Jersey 
State  Board  of  Agriculture  and  the  New  Jersey  State 
Grange,  as  well  as  their  hearty  co-operation  with,  and 
cordial  appreciation  of,  all  genuine  efforts  made  in  behalf 
of  agricultural  education  in  the  public  schools  of  the 
State. 

X.  B.  V. 

Niw  Brunswick,  X.  J. 
November,  1886. 


CONTENTS. 


CHAPTIR  PAGI 

I.  The  Constituents  of  Plants 7 

II.  Origin  and  Formation  of  Soils 18 

III.  Composition  of  Soils 29 

IV.  The  Improvement  of  Soils 41 

V.  Natural  Manures 52 

VL  Artificial  and  Concentrated  Manures  ;  Ni- 
trogenous Materials 68 

VII.    Artificial  and  Concentrated  Manures  ;  Phos- 
phates     80 

VIII.    Artificial   and    Concentrated   Manures  ;    Su- 
perphosphates and  Potash  Salts     ....      90 

IX    Artificial  Manures  or  Fertilizers  ;  Methods 

of  Buying  ;  Valuation  ;  Formulas  ....    101 

X.    The  Rotation  of  Crops 113 

XI.  The  Selection  of  Seed  ;  Farm  Crops  and 
Their  Classification  ;  Cereals  ;  Grasses  ; 
Pastures  ;  Roots  ;  Tuhers  ;  and  Market- 
Garden  Crops 122 

XII.    The  Growth  of  Animals  ;  The  Constituents  of 
Animals  and  Animal  Food  ;    The   Charac- 
ter and  Composition  of  Fodders  and  Feeds,    137 
5 


6  CONTENTS. 

CHAPTER  r.v  II 

XIII.  The    Digestibility    op    Fodders    and    Feeds  ; 

Feeding  Standards  ;  Nutritive  Ratio  ;  The 
Exchange  of  Farm  Products  for  Concen- 
trated Feeds 154 

XIV.  Principles  of  Breeding  ;  The  Pure  Breeds  of 

Farm  Stock    .    .    .• 170 

XV.    The  Products  of  the  Dairy  ;  Their  Character 

and  Composition  ;  Dairy  Management     .    .    182 

Appendix  — 

Tables 199 

Index 209 


'  C 
c 


FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER  I. 

The  Constituents  of  Plants;  Plant  Growth. 

Parts  of  Plants.  —  Most    agricultural  plants   possess 

three  distinct  parts,  —  the  root,  the  stem,  and  the  leaf. 

The  main  uses  of  the  root  are  to  secure  food  from  the  soil, 

and  to  serve  as  a  support  to  the  plant  during  its  period 

of  life.     The  stem  acts  as  a  support  for  the  leaves,  as 

a  medium  for  the  circulation  of  food  through  the  plant, 

from  the  leaf  to  the  root  and  from  the  root  to  the  leaf, 

and  as  a  storehouse  of  nutriment  for  future  growth.     The 

>V  leaves  secure  food  from  the  atmosphere,  and  permit  the 

(      escape  into  the  air  of  the  water  taken  up  by  the  roots. 

^         These  different  parts  all  co-operate,  or  work  together, 

1      to  secure  and  distribute  the  constituents  necessary  to  the 

complete   growth   and   development  of    the  whole  plant. 

What  is  plant  food,  or  of  what  constituents  is  a  plant 

composed,  is  a  question  of  the  first  importance  in  a  study 

of  the  growth  of  plants. 

The  Water  contained  in  Plants.  —  A  plant  in  the 
first  place  is  composed  of  two  distinct  classes  of  sub- 
stances, —  water  and  dry  matter.  Water  is  contained  in 
all  growing  plants;  forest  and  fruit  trees  seldom  contain 

7 


8  FIRST  PRINCIPLES  OF  AGRICULTURE. 

less  than  four-fifths,  while  vegetables  and  young  plants 
are  frequently  nine-tenths  water. 

When  plants  are  removed  from  the  soil,  and  brought  in 
contact  with  the  air  and  warmth,  a  large  part  of  the  water 
contained  in  them  escapes  in  the  form  of  water  vapor ; 
they  become  what  is  termed  "  air  dry."  The  proportion  of 
water  lost  in  this  way,  and  the  time  or  rapidity  of  loss, 
depend  upon  the  moisture  contained  in  them,  and  the 
warmth  of  the  atmosphere;  the  drier  and  warmer  the 
atmosphere,  the  greater  the  loss  of  water.  This  loss  of 
water  is  nicely  illustrated  in  hay-making,  the  time  re- 
quired to  dry  or  cure  depending  upon  the  kind  of  plant 
and  the  character  of  the  weather. 

Air-dry  Plants.  —  In  temperate  climates,  air-dry  plants 
still  contain  from  eight  to  twelve  per  cent  of  water.  To 
effect  its  complete  removal  they  are  heated  to  a  temper- 
ature of  212°  F.,  that  of  boiling  water,  until  there  is  no 
further  loss  of  weight.  The  portion  remaining  after  the 
drying  is  termed  the  "  dry  matter."  The  dry  matter  of 
plants  contains  all  the  constituents  of  their  growth;  that 
is,  all  those  necessary  for  perfect  growth,  no  one  of  which 
can  be  removed  without  destroying  it. 

Water,  while  it  is  essential  in  the  growth  of  plants 
and  serves  a  useful  purpose,  is  not  a  constituent  in  the 
same  sense  as  those  which  are  contained  in  the  dry 
matter,  since,  as  has  already  been  noted,  it  can  be  removed 
without  destroying  the  structure  and  form  of  the  plant. 

The  Total  Dry  Matter.  —  The  total  dry  matter  of 
plants  contains  all  those  substances  or  compounds  which 
are  useful  for  the  purposes  for  which  they  are  grown. 
The  constituents  contained  in  it  may  also,  for  convenience 


THE  CONSTITUENTS  OF  PLANTS.  9 

of  study,  be  divided  into  two  classes:  first,  those  which 
are  lost  or  driven  away  by  burning,  or  are  capable  of  being 
burned ;  and  second,  those  which  are  contained  in  the  ash 
or  residue  after  burning.  The  first  are  called  "combus- 
tible" or  burnable  constituents;  the  others  are  called  the 
"  incombustible  "  or  ash  constituents. 

The  part  that  is  removed  by  burning  contains  the  con- 
stituents that  have  been  derived  largely  from  the  air, 
while  the  remainder  contains  the  mineral  substances  which 
have  been  derived  largely  from  the  soil.  The  burning 
of  wood  illustrates  the  separation  of  these  two  classes 
of  constituents  and  the  proportions  of  each. 

Each  one  of  the  constituents  contained  in  a  plant  is 
a  distinct  chemical  element;  and  the  number  and  kind 
which  have  been  found  to  be  absolutely  essential  to  the 
growth  of  plants  are  carbon,  oxygen,  nitrogen,  hydrogen, 
potassium,  magnesium,  calcium,  iron,  phosphorus,  and 
sulphur.  These  are  called  plant-food  elements,  and  all 
healthy  plants  contain  them;  if,  by  any  chance,  any 
one  of  them  could  not  be  obtained,  the  plant  could  not 
make  normal  growth,  and  in  this  sense  no  one  of  them 
is  of  more  importance  than  another. 

Besides  these,  however,  the  chemical  elements,  silicon, 
chlorine,  sodium,  manganese,  and  sometimes  others,  do 
exist  in  the  plant,  though  plants  can  be  grown  without 
them.  Thus,  at  most,  but  fourteen  only  of  the  seventy 
known  chemical  elements  are  necessary  for  the  growth 
of  a  plant,  and  form  its  food.  The  large  number  of 
different  species  and  varieties  of  plants  now  existing  is, 
however,  capable  of  being  produced  from  them,  the 
different  properties   and   forms   being  entirely  due  to  a 


10  FIRST  PRINCIPLES  OF  AGRICULTURE. 

different  grouping  or  combining  of  the  constituents  in 
the  plant. 

Source  of  Plant-food  Elements.  —  Plants  derive  the 
elements  of  their  growth  from  two  sources,  —  the  atmos- 
phere and  the  soil.  The  atmosphere,  while  the  original 
source  of  carbon,  hydrogen,  oxygen,  and  nitrogen,  fur- 
nishes direct  chiefly  the  element  carbon.  Hydrogen  and 
oxygen  are  furnished  mainly  through  the  soil  in  the 
form  of  water;  though  the  original  source  is  the  atmos- 
phere, where  they  exist  in  the  form  of  "water  vapor." 
Nitrogen  is  also  largely  taken  up  by  the  roots  of  plants ; 
though  certain  classes  of  plants,  as  we  shall  see  later, 
have  the  power,  under  proper  conditions,  of  obtaining  it 
from  the  atmosphere,  of  which  it  constitutes  about  four- 
fifths  of  the  whole  bulk. 

The  Proportion  of  Food  derived  from  the  Air. — 
These  constituents  derived  from  the  atmosphere  constitute 
about  ninety-five  per  cent  of  the  total  dry  matter  of 
plants,  of  which  carbon  constitutes  nearly  one-half;  the 
remaining  five  per  cent  is  the  "  incombustible "  or  ash 
constituents.  The  soil  is  the  exclusive  source  of  these 
elements;  they  are,  however,  indispensable,  for  without 
them  the  carbon  of  the  atmosphere,  the  hydrogen  and 
oxygen  of  the  water,  and  the  nitrogen  of  the  soil  or  at- 
mosphere, would  not  have  been  able  to  enter  into  plant  life. 
The  atmospheric  constituents  are  usually  termed  the 
"  organic ; "  and  the  soil  constituents,  the  "  inorganic," 
or  ash  elements.  This  distinction,  though  not  entirely 
accurate,  serves  a  good  purpose  in  helping  to  get  a  proper 
understanding  of  the  relations  of  the  compounds  formed 
in  the  plant. 


THE  CONSTITUENTS   OF  PLANTS.  11 

The  Essential  Constituents,  How  Determined. — 
The  sources  of  the  chemical  constituents  necessary  to  the 
growth  of  plants,  as  well  as  their  kind  and  number, 
have  been  determined  by  careful  experiments,  conducted 
in  the  following  manner :  — 

Sand,  which  is  an  inert  substance,  is  thoroughly  burned, 
which  destroys  all  combustible  matter;  then  carefully 
washed,  which  removes  all  traces  of  plant-food ;  a  por- 
tion is  then  put  in  a  suitable  jar  or  box,  and  seed  of 
wheat  or  corn  planted,  and  moistened  with  pure  distilled 
water.  The  sand  contains  no  food,  yet  the  weight  of 
the  dry  matter  in  the  growth  made  is  shown,  by  careful 
analysis  of  both  seed  and  plant,  to  be  much  greater  than 
the  weight  of  the  seed  planted;  also,  that  the  increase 
in  weight  consists  entirely  of  carbon,  hydrogen,  and 
oxygen,  which  must  have  been  obtained  from  the  air 
and  water.  This  establishes  the  fact  that  air  and  water 
furnish  food,  and  that  this  food  consists  of  atmospheric 
elements. 

In  another  series  of  experiments,  to  the  sand  and  water, 
in  one  experiment,  the  various  essential  ash  or  mineral 
constituents  alone,  are  added;  to  another,  nitrogen  alone; 
while  to  a  third,  both  the  ash  constituents  and  nitrogen 
are  added.  In  the  first  and  second  experiments,  but  little 
addition  is  made  in  the  weight  of  the  crop  over  that 
secured  when  water  alone  was  added ;  the  growths  are  not 
perfect;  minerals  alone,  and  nitrogen  alone,  are  not  suffi- 
cient. In  the  third  experiment,  however,  the  crop  is  fully 
developed  in  every  particular,  proving  that  the  addition 
of  minerals  and  nitrogen  is  absolutely  essential. 

The  necessity  of  each  of  the  mineral  constituents,  and 


12  FIRST  PRINCIPLES  OF  AGRICULTURE. 

their  influence,  are  shown  by  omitting  in  each  case,  in 
another  series  of  experiments,  one  of  the  mineral  ele- 
ments; the  crop  secured  in  each  experiment  is  found  to 
be  imperfect.  Perfect  growth  is  only  reached  when  all 
the  elements  named  are  present. 

Pood  obtained  from  the  Atmosphere.  —  The  leaves 
and  roots  are  called  organs  of  nutrition;  the  leaves  take 
material  from  the  air,  the  roots  from  the  soil. 

The  dry  substance  of  a  plant  is  made  up  chiefly  of 
carbon,  and  the  proper  absorption  of  this  element  depends 
upon  the  activity  of  the  leaves.  The  leaf  is  made  up  of 
rows  of  cells,  placed  side  by  side,  which  in  the  under 
portion  are  loosely  held  together,  forming  "air  spaces" 
between  them,  and  over  the  whole  leaf  there  is  a  thin, 
transparent  skin.  This  skin,  called  the  "epidermis,"  is 
not  entire,  but  is  dotted  with  little  holes  called  "  stomata ; " 
through  these  the  atmospheric  air  passes  freely  into  the 
cellular  spaces  in  the  leaf,  and  through  the  porous  walls 
of  the  leaf  cells,  which  contain  a  green  substance  called 
"chlorophyll." 

In  these  cells,  containing  chlorophyll,  the  carbonic  acid 
of  the  air  is  broken  up  through  the  influence  of  light  and 
warmth,  and  the  oxygen  set  free  and  the  carbon  retained. 
This  process  is  called  "assimilation,"  and  is  active  only 
during  the  daytime ;  during  the  night  the  food,  formed  by 
day,  undergoes  a  change,  whereby  it  can  be  transferred  in 
solution  to  the  places  where  it  is  needed.  Daylight,  as 
also  the  presence  of  iron  in  the  plant,  is  necessary  for 
the  formation  of  chlorophyll. 

In  the  daytime,  growing  plants  purify  the  air  by  con- 
suming the  carbon ;  in  the  night,  the  process  is  reversed, 


THE  CONSTITUENTS  OF  PLANTS.  18 

oxygen  being  then  consumed.  The  quantity  of  oxygen 
set  free  by  young  plants  is,  however,  greatly  in  excess  of 
that  consumed.  The  food  directly  supplied  by  the  atmos- 
phere is,  therefore,  chiefly  carbon. 

The  carbon  absorbed  by  the  plant,  in  connection  with 
the  hydrogen  and  oxygen  of  the  water,  forms  starch,  dex- 
trine, sugar,  fat,  cellulose,  substances  serviceable  in  the 
growing  plant,  and  to  be  stored  away  for  future  use  in 
seeds,  roots,  and  stems ;  and  the  same  elements,  together 
with  nitrogen  and  a  little  sulphur,  form  the  albuminoids. 
All  of  these  are  vegetable  substances  with  which  we  are 
familiar,  and  which  are  termed  "organic." 

Pood  obtained  from  the  Soil.  —  Roots  are  of  two 
kinds,  —  the  "  tap  root,"  the  chief  use  of  which  is  to  sus- 
tain the  plant  in  an  upright  position;  and  the  "fibrous 
root,"  which  is  engaged  mainly  in  absorbing  food  from 
the  soil.  These  roots  are  made  up  of  cells,  through  the 
walls  of  which  solid  matter  cannot  pass ;  all  food  absorbed 
by  the  root  must  be  in  solution.  The  surface  membrane 
of  the  root,  unlike  that  of  the  leaf,  is  not  full  of  holes ; 
the  absorption  of  solids  is,  therefore,  impossible.  The 
absorption  of  the  solution  by  the  root  is  obtained  by 
means  of  what  is  called  "diffusion."  By  this  means 
water  is  absorbed,  and,  with  the  water,  the  dissolved 
food  elements  usually  contained  in  the  ash  of  plants.  The 
absorption  of  food  is,  however,  not  confined  to  the  taking 
up  of  ready  formed  solutions. 

The  root  grows  at  its  tip,  and  it  is  through  the  delicate 
cells  located  there  that  the  plant  absorbs  nutriment.  The 
tips  are  protected  by  a  sheath,  or  cover,  of  dead  or  dying 
cells,  which  protects  the  delicate  fibres,  and  permits  the 


14  FIRST  PRINCIPLES  OF  AGRICULTURE. 

root  to  penetrate  the  soil  without  injury.  The  acid  sap 
or  fluid  which  is  produced  by  the  root,  hair,  or  cell,  when 
it  comes  in  contact  with  soil  particles,  has  a  solvent  effect 
upon  them ;  thus  is  insoluble  matter  in  the  soil,  containing 
ash  ingredients,  made  soluble  to  the  plant. 

These  elements  derived  from  the  soil  are,  however,  not 
taken  up  in  the  form  of  individual  chemical  elements,  but 
chiefly  as  acid  or  salts.  Nitrogen,  for  instance,  is  com- 
bined with  oxygen  to  form  nitric  acid ;  which,  united  with 
bases  like  sodium  or  calcium,  forms  sodium  or  calcium 
nitrates.  The  very  weak  solutions  of  the  compounds 
taken  up  by  the  roots  are  concentrated  in  the  upper  part 
of  the  plant,  owing  to  the  rapid  evaporation  of  the  water 
through  the  leaves,  and  are  employed  in  the  formation  of 
new  tissues. 

Supply  of  Food  Constituents.  —  The  atmosphere 
contains  relatively  a  very  small  proportion  of  carbonic 
acid,  from  which  the  carbon  is  obtained ;  it  is  less  in  the 
open  country  and  over  large  bodies  of  water,  and  more  in 
the  vicinity  of  towns,  yet  the  supply  in  the  aggregate  is 
enormous,  and  is  sufficient  to  meet  all  the  demands  of 
vegetation  for  carbon. 

The  atmosphere  also  contains  small  quantities  of  nitro- 
gen, existing  both  as  ammonia  and  as  nitrates ;  these  are 
brought  to  the  earth  by  means  of  dew  and  rain,  and  thus 
act  as  a  direct  source  of  this  element  to  plants.  The 
amount  so  provided  is,  however,  insufficient  for  the 
entire  needs  of  vegetation. 

The  moisture,  or  "  water  vapor  "  in  the  atmosphere  does 
not,  to  any  great  extent,  serve  to  supply  the  plant  with 
water,  the   absorption   of   water  being  a  function  of   the 


THE  CONSTITUENTS  OF  PLANTS.  15 

roots  rather  than  the  leaves.  The  leaves  absorb  water 
when  there  is  an  insufficient  supply  in  the  soil,  or  when 
the  weather  is  such  as  to  cause  a  very  rapid  exhalation 
from  the  leaves.  The  supply  of  the  mineral  constituents 
depends  upon  the  character  and  composition  of  the  soil, 
upon  the  season,  and  climate ;  these  conditions  are  not  uni- 
form, hence  the  increased  variation  in  the  character  of  the 
natural  vegetation  found  in  different  parts  of  the  world. 

Functions  of  the  Constituents.  —  The  exact  work 
that  each  constituent  performs  in  plant  nutrition  has  not 
yet  been  definitely  determined.  It  has  been  shown  that 
nitrogen  is  of  vital  importance,  since  it  is  an  essential 
constituent  of  the  living  principle  of  plants  called  "pro- 
toplasm." Phosphorus  and  sulphur  have  been  found 
essential  constituents  in  the  formation  of  albuminoids,  a 
very  important  compound  of  all  plants.  Potash  is  neces- 
sary to  the  formation  and  distribution  of  starch,  while  the 
green  color  of  plants,  or  chlorophyll,  cannot  be  formed 
without  iron.  All  the  constituents  mentioned  are  neces- 
sary, and  are  concerned  in  the  various  processes  which 
result  in  the  perfect  plant. 

The  Natural  Tendency  of  Plant  Growth.  —  The  ulti- 
mate object  of  all  plants  in  their  natural  state  is  to  form 
seed,  or  the  beginning  of  new  plants.  The  seed  of  every 
plant  contains  within  itself  a  sufficiency  of  food  to  nourish 
the  germ  till  the  root  and  leaves  of  the  new  plant  are 
sufficiently  developed  to  acquire  food  from  the  sources 
mentioned. 

Germination  :  the  Conditions  Necessary.  —  The 
first  evidences  of  growth  are  shown  in  the  germination 
or  sprouting  of  the  seed.     This  beginning  depends  chiefly 


16  FIRST  PRINCIPLES   OF  AGRICULTURE. 

upon  three  conditions,  —  first,  the  presence  of  moisture ; 
second,  of  warmth,  or  a  proper  degree  of  temperature ; 
and  third,  the  access  of  air.  The  seed  of  the  wheat  plant, 
for  instance,  will  retain  its  form  and  remain  a  seed  for  a 
long  time  if  kept  dry.  As  soon  as  it  is  enabled  to  absorb 
moisture  it  increases  in  size,  oxygen  is  absorbed  from  the 
air,  and  heat  develops ;  it  separates  the  germ,  and  is  no 
longer  a  seed,  but  a  young  plant.  Seeds  do  not  germi- 
nate below  a  certain  temperature,  usually  about  37°  F. ; 
the  warmth  necessary  for  germination  is,  however,  differ- 
ent for  different  seeds.  Wheat  will  not  germinate  below 
41°  F.,  and  corn  below  49°  F.  There  is  also  a  certain 
temperature  above  which  seed  will  not  germinate;  the 
higher  limit  is  108°  F.  for  wheat,  and  115°  F.  for  corn. 
The  temperature  of  most  rapid  germination  lies  between 
79°  F.  and  94°  F. 

The  presence  of  air  is  universal,  and  care  in  this 
respect  is  only  important  when  plants  are  grown  in 
comparative  confinement. 

Duration  of  Life.  —  Plants  which  germinate,  grow, 
and  produce  flower,  fruit,  and  seed  in  one  year,  and  then 
die,  are  called  "annuals."  Wheat,  rye,  oats,  buckwheat, 
peas,  and  beans  are  good  examples  of  annual  plants. 
Certain  other  plants  require  two  seasons  for  this  work; 
these  are  called  "  biennials."  During  the  first  season,  the 
organs  of  growth  are  developed,  viz.,  the  root  and  leaf; 
the  second  season,  the  flower,  fruit,  and  seed  are  formed, 
after  which  the  plants  die.  Examples  of  biennial  plants 
are  cabbages,  turnips,  parsnips,  celery,  lettuce,  beets,  etc. 

In  order  to  secure  seed  it  is  not  necessary  that  the 
plants  remain  in  the  ground  throughout  the  winter.     Cer- 


THE  CONSTITUENTS   OF  PLANTS.  17 

tain  quick  growing  biennials,  as  radishes,  may  produce 
seed  in  one  year,  if  removed  from  the  soil  after  the  root 
is  full  grown,  topped,  and  transplanted. 

"Perennials"  are  plants  that  live  for  more  than  two 
years ;  timber-trees,  fruit-trees,  berries,  grape-vines,  etc., 
are  good  examples,  though  perennials  are  not  confined  to 
trees  and  shrubs ;  asparagus,  a  number  of  the  clovers, 
and  various  grasses,  also  belong  to  this  group. 

Plant  Development.  —  The  development  of  the  plant 
after  germination  is  not  uniform ;  the  substances  obtained 
by  the  roots  are  greatest  in  the  young  plant,  which  is 
always  rich  in  nitrogen  and  ash  elements.  As  the  plant 
grows,  the  proportion  of  food  derived  from  the  atmos- 
phere through  the  action  of  the  leaves  steadily  increases. 

The  wheat  crop  contains  practically  all  of  its  nitrogen 
and  potash  when  in  full  bloom ;  carbon  increases  as  long 
as  the  plant  remains  green.  When  the  seeds  begin  to 
form,  the  food  gathered  by  the  leaf  and  root  is  largely 
transferred  from  the  stem  and  leaf  of  the  plant,  and 
concentrated  in  the  seed. 

Cereals  and  grasses  cut  while  the  crop  is  green  are 
much  richer  in  nutritive  matter  than  when  they  are 
allowed  to  ripen  seed.  In  such  crops  as  turnips,  beets, 
and  potatoes,  the  development  of  root  and  leaf  is  the 
same  as  in  wheat;  but  at  the  completion  of  growth,  food 
is  stored  up  or  contained  in  the  root,  or  tuber,  and  the 
leaves  die  after  the  food  in  the  plant  has  been  largely 
transferred.  In  trees,  the  plant-food  gathered  by  the 
root  is  concentrated  by  the  end  of  summer  in  the  pith 
of  the  tender  branches  and  in  buds,  and  serves  as  food 
for  the  new  growths  of  another  season. 


18  FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER   n. 
Origin  and  Formation  of  Soils. 

Soils :  Their  Origin,  Formation,  and  Classification. 
—  Every  growing  thing  can  be  traced  back  to  two  primary 
sources,  —  the  atmosphere  and  the  soil.  Every  chemical 
element  contained  in  plants  or  in  animals  produced  from 
plants  can  be  found  either  in  the  soil  or  atmosphere. 

The  constituents  which  plants  derive  from  the  atmos- 
phere are  so  abundant  everywhere  that  the  continuous 
growth  of  maximum  crops  cannot  exhaust  them,  and  no 
particular  efforts  are  required  to  increase  their  efficiency 
to  the  plant.  The  constituents  of  the  soil  are  much  less 
abundant,  and  the  power  of  the  plant  to  secure  them 
depends  very  largely  upon  the  effort  of  the  farmer.  To 
the  farmer,  then,  the  soil  is  the  object  of  first  attention. 

What  is  a  Soil?  —  The  soil  is  the  name  given  to  that 
part  of  the  earth  that  can  be  cultivated,  and  in  which 
plants  can  grow. 

Origin  of  Soils.  —  Soils  are  derived,  directly  or  in- 
directly, from  the  rotting  or  decay  of  rocks.  If  all  the 
earthy  matter  which  composes  soils  could  be  removed 
from  the  surface  of  the  earth,  the  remainder  would  be 
solid  rock.  Rocks  have  been  formed  by  the  action  of 
fire  and  water ;  hence  they  are  classed  as  "  igneous,"  that 
is,  produced  by  the  action  of  fire,  or  "  aqueous,"  produced 


ORIGIN  AND  FORMATION  OF  SOILS.  19 

by  the  action  of  water.  The  igneous  rocks  form  but  a 
small  proportion  of  the  outer  rocks  of  the  world;  yet 
they  are  of  great  importance,  because  it  is  through  their 
decay  or  breaking  up  that  the  other  rocks  have  been 
formed. 

The  most  important  of  the  igneous  rocks  are  granite 
and  trap.  These  contain  silica  and  alumina  as  their  chief 
constituents,  and  greater  or  less  amounts  of  potash,  lime, 
magnesia,  iron,  and  the  other  mineral  constituents  of 
plants.  These  rocks  are  also  called  "  primary  rocks," 
because  they  are  supposed  to  constitute  the  primary  or 
first  crust  of  the  earth,  and  to  be  similar  in  character 
and  composition  to  the  now  molten  interior  of  the  earth. 
This  view  is  based  upon  the  fact  that  the  lava  ejected 
from  active  volcanoes  resembles  in  composition  the  trap 
rocks. 

The  trap  rocks  consist  mainly  of  two  minerals,  feldspar 
and  hornblende.  Feldspar  is  particularly  rich  in  potash 
and  soda,  and  poor  in  lime  and  magnesia.  Hornblende 
is  poor  in  potash  and  soda,  and  rich  in  lime  and  mag- 
nesia. Granite  rocks  consist  mainly  of  quartz,  feldspar, 
and  mica.  Quartz  is  almost  pure  silica;  while  mica  con- 
tains nearly  all  the  compounds  found  in  both  feldspar  and 
hornblende,  and  is  one  of  the  most  abundant  minerals. 

The  aqueous  rocks  are  formed  from  the  minerals  con- 
tained in  igneous  rocks,  the  proportion  of  the  different 
constituents  contained  in  them  depending  upon  the  method 
of  their  formation.  Limestone  and  red  sandstone  are 
good  examples  of  aqueous  rocks. 

Subsoil.  —  The  subsoil  lies  immediately  underneath 
the  soil,  and  rests  upon  the  solid  rock.     The  main  dis- 


20  FIRST  PRINCIPLES  OF  AGRICULTURE. 

tinction  between  soil  and  subsoil  is  that  the  soil  contains 
more  organic  or  vegetable  matter,  is  more  finely  divided, 
and  is  less  compact  than  the  subsoil  The  subsoil  may 
be  regarded  as  something  between  the  soil  and  rock, 
and  partaking  in  part  of  the  characteristics  of  both. 
The  subsoil  serves  to  gradually  supply  the  constituents 
that  are  removed  by  crops  from  the  surface  soil,  and 
also  performs  important  functions  as  a  reservoir  of 
moisture,  and  as  a  medium  for  the  roots  of  plants.  Its 
character  thus  materially  modifies  the  fertility  and  pro- 
ductiveness of  the  soil  proper. 

The  Formation  of  SoiL  —  Certain  agencies  are  con- 
stantly at  work  converting  rock  into  soiL  This  gradual 
conversion  is  termed  "weathering,"  and  is  observed  on 
all  sides.  The  rapid  crumbling  of  shale,  so  familiar  in 
2xew  Jersey,  on  exposure  to  the  atmosphere,  is  an  ex- 
cellent illustration  of  this  process,  —  the  air,  temperature, 
and  water  all  playing  an  important  part. 

The  Action  of  the  Atmosphere.  —  The  atmosphere 
causes  what  is  termed  "  oxidation,"  a  slow  burning  or 
decay.  The  oxygen  of  the  air  combines  with  the  miner- 
als, forming  new  substances  called  "oxides."  A  familiar 
illustration  of  this  process  is  seen  when  iron  is  exposed 
to  the  air;  the  red  rust  that  forms  is  an  oxide  of  iron, 
a  substance  very  different  from  the  iron  itself. 

The  Influence  of  "Water.  —  The  most  powerful  agent 
in  the  rotting  or  breaking  up  of  rocks  is  water.  It  acts 
both  mechanically  and  chemically.  Most  rocks  contain 
cracks  or  fissures  into  which  the  water  readily  penetrates ; 
by  freezing  the  water  expands,  and  forces  the  rock  apart. 
Thus  the  solid  rock  is  gradually  separated  into  fragments 


ORIGIN  AND  FORMATION  OF  SOILS.  21 

of  different  sizes.  The  force  of  the  water  in  rains  and 
streams  grinds  the  fragments  together  continually,  wear- 
ing them  smaller,  and  the  smallest  are  first  carried  away 
by  the  water  to  lower  levels. 

The  overflow  of  rivers  always  leaves  a  deposit  of  soil 
particles,  more  or  less  finely  divided,  carried  in  suspen- 
sion in  the  water;  this  sediment  gradually  accumulating 
forms  soil.  What  are  termed  by  geologists  "sedimentary, 
or  aqueous,  rocks  "  have  also  been  formed  by  the  action 
of  water,  followed  by  heat  or  pressure,  or  both. 

Water  also  has  a  decided  effect  chemically.  The 
carbonic_acid  in  the  water  absorbed  from  the  atmosphere 
dissolves  certain  of  the  chemical  ingredients  of  the  soil, 
particularly  Lime,  though  its  solvent  effect  is  not  confined 
to  this  substance;  soda,  potash,  silica,  and  iron  are  also 
attacked  to  a  greater  or  less  degree. 

The  Growth  of  Plants.  —  The  growth  of  plants  is 
also  active  in  the  rotting  of  rocks.  In  their  growth 
the  roots  penetrate  the  crevices  and  force  the  particles 
of  rock  to  separate ;  they  also  attack  and  absorb  certain 
portions  of  the  constituents  that  are  made  soluble.  In 
the  decay  of  plants,  the  soil  is  kept  moist,  gases  are 
generated  and  absorbed  by  the  water,  which,  again  pene- 
trating the  rocks,  has  a  solvent  effect  upon  them. 

It  is  a  matter  of  common  observation  to  see  rocks 
covered  with  the  lower  orders  of  plants,  like  lichens 
and  mosses ;  the  removal  of  these  frequently  shows  the 
rocks  furrowed  and  eaten  into  by  the  roots,  due  to  the 
action  described.  This  growth  and  this  decay  of  vege- 
table life,  continued  through  a  long  series  of  years,  gradu- 
ally deepen  the  soil,  and  prepare  it  to  produce  the  higher 


22  FIRST  PRINCIPLES  OF  AGRICULTURE. 

order  of  agricultural  plants,  or  those  useful  as  food  foi 
man. 

Earth  Worms.  —  Earth  worms  and  other  living  crea- 
tures living  in  the  ground  also  aid  in  preparing  the  soil 
for  the  growth  of  plants.  They  burrow  deep  into  the 
ground;  the  passages  thus  made  aid  in  drainage  and 
circulation  of  air,  and  facilitate  the  penetration  of  roots, 
which  increases  their  power  to  secure  food.  They  also 
drag  into  their  underground  passages  considerable  vege- 
table matter,  which  in  its  decay  aids  in  forming  true  soil. 
—7  Movement  of  Soils.  —  While  our  present  soil  remains 
almost  constant  in  quantity,  the  parts  removed  by  various 
causes  being  supplied  by  the  gradual  decay  of  the  rocks, 
the  same  agencies  which  form  soils,  particularly  weather 
action,  are  wasting  or  carrying  them  away.  Soil  is  almost 
constantly  moving;  it  is  thinnest  at  the  top  of  the  hill, 
and  deepest  in  the  valley.  This  is  very  noticeable  in 
mountainous  or  hilly  districts;  great  furrows  are  formed 
in  the  hillsides  after  heavy  rains,  the  swollen  and  muddy 
streams  carrying  the  soil  in  suspension  to  lower  parts 
of  the  land. 

Soils  in  Place.  —  Soils  which  have  been  formed  from 
the  decay  of  the  underlying  rock  are  called  sedentary 
soils,  or  soils  in  place;  they  have  not  been  moved  from 
the  place  in  which  they  originated.  These  partake  of  the 
nature  and  composition  of  the  rock  underneath;  though, 
from  the  method  of  their  formation,  viz.,  the  growth 
and  decay  of  plants,  they  contain  considerable  vegetable 
matter  obtained  from  the  atmosphere. 

Transported  Soils.  —  Transported  soils  are  those 
which    have    been    moved    from    the   place    where  they 


ORIGIN  AND  FORMATION  OF  SOILS.  23 

originated,  and  deposited  from  water  or  ice.  The  former 
are  called  "  alluvial ; "  these  occur  not  only  in  valleys 
and  river-beds,  but  in  inland  places,  where  they  have 
been  deposited  in  lakes  or  other  bodies  of  water.  Those 
deposited  from  ice  are  called  "drift  soils;"  these  have 
been  formed  by  the  action  of  "glaciers,"  vast  bodies  of 
ice  moving  like  a  river,  which  carry  considerable  quanti- 
ties of  earth  as  well  as  numerous  rocks. 

The  results  of  glacial  action  are  found,  not  only  in 
valleys,  but  in  high  mountains,  where  rocks  show,  by 
well-defined  scratches,  the  wearing  and  grinding  effect  of 
the  moving  ice. 

Prift  soils  are  distinguished  from  all  others  by  the 
presence  of  rounded  rocks  or  bowlders,  and,  though  not 
uniform  either  in  composition  or  character,  are  usually 
fertile,  the  ferti'ity  being  due  chiefly  to  the  bringing 
together,  from  numerous  sources,  of  a  variety  of  min- 
eral substances. 

Classification  of  Soils.  —  The  principal  ingredients., 
of  soils  are  sand,  clay,  carbonate  of  lime,  and  vegetable 
or  organic  matter.  They  are,  therefore,  divided  into  four 
natural  classes;  viz.,  sandy,  clayey,  limy,  and  peaty,  ac- 
cording to  the  greater  proportion  in  each  case  of  one 
of  these  four  ingredients. 

What  is  Sand?  —  Sand  or  silica  is  composed  of  the 
mineral  silicon  united  with  the  chemical  element  oxygen, 
and  does  not  serve  directly  as  food  for  plants.  A  soil 
consisting  entirely  of  sand  would  be  useless  to  the  farmer, 
for  he  could  produce  nothing  from  it  in  its  natural  con- 
dition. It  possesses  diatinct:prQperties,  however,  which 
render  soils  containing  considerable  sand  light  and  open, 


24  FIRST  PRINCIPLES  OF  AGRICULTURE. 

and  therefore  permeable  to  air,  moisture,  and  warmth. 
The  stony  particles  of  sand  are  also  rapidly  heated  by 
the  rays  of  the  sun,  thus  very  greatly  influencing  the 
temperature  of  the  soil. 

1/  What  is  Clay?  —  Pure  clay  contains  silica,  together 
with  alumina,  a  compound  of  aluminum  and  oxygen. 
From  a  "chemical  point  of  view,  pure  clay  would  be 
quite  as  useless  as  sand  as  a  source  of  plant-food,  neither 
silica  nor  alumina  being  essential  constituents  of  plants. 
The  properties  of  clay  are  almost  the  reverse  of  those 
of  sand.  Particles  of  sand  do  not  adhere  to  each  other 
—  moist  sand  pressed  firmly  in  the  hand  will  fall  apart 
immediately  the  pressure  ceases ;  particles  of  clay,  on  the 
contrary,  readily  adhere  to  each  other,  and,  when  moist, 
can  be  moulded  into  any  desired  shape,  which  is  retained ; 
on  heating,  the  particles  adhere  still  more  strongly,  a 
characteristic  taken  advantage  of  by  the  manufacturers 
of  brick,  tile,  etc.  Sand  from  its  porous  nature  rapidly 
loses  water;  clay  from  its  compact  nature  retains  mois- 
ture. Sand  absorbs  heat  rapidly,  and  soon  becomes  dry ; 
clay  absorbs  heat  more  slowly,  and  remains  cool.  Clay, 
like  sand,  is,  however,  a  valuable  constituent  of  soils ;  its 
tenacious  character  enabling  it  to  retain  both  moisture 
and  the  useful  constituents  applied  in  manures. 

Lime.  —  The  lime  of  soils  usually  exists  in  the  form 
of  carbonate  of  lime,  or  limestone.  Limestone  is  a  valu- 
able ingredient  of  soils,  not  only  because  it  furnishes 
the  important  constituent  of  plants,  calcium,  but  because 
of  its  relative  ease  of  decomposition,  ancTof  its  valuable 
action  upon  and  reaction  with  other  soil  constituents ; 
it    aids  in  the  decay  of  vegetable  matter,   and   in  the 


OBIGIN  AND  FOBMATION  OF  SOILS.  25 

formation  of  nitrates.  It  exerts  a  favorable  physical 
effect  upon  soils;  its  presence  helps  to  separate  the  adhe- 
sive particles  of  clay,  and  makes  heavy  soils  loose  and 
friable,  which  permits  the  easy  passage  of  water  through 
them.  Lime  also  increases  the  absorbing  and  retaining 
power  of  sandy  soils,  by  causing  the  particles  to  adhere 
more  closely  to  each  other. 
'  Humus.  —  The  decaying  vegetable  matter  in  soils, 
which  is  made  up  of  carbon,  oxygen,  hydrogen,  and 
nitrogen,  is  called  "humus."  In  virgin  soils  it  is  derived 
from  the  dead  roots  and  leaves  of  a  former  vegetation. 
It  has  a  dark  brown  or  blackish  color.  Leaf  mould, 
found  in  forests,  is  largely  composed  of  humus.  It  was 
believed  at  one  time  that  humus  served  as  a  direct  food 
for  plants,  but  this  idea  has  been  proved  to  be  incorrect; 
it  is  the  final  products  of  its  decay,  chiefly  carbonic  acid, 
ammonia,  and  water,  that  serve  as  plant-food. 

Humus  is  a  very  useful  ingredient  in  all  kinds  of 
soils,  though  a  soil  may  contain  too  much  decaying 
organic  matter.  Humus  improves  sandy  soils,  not  only 
on  account  of  the  nitrogen  and  other  plant-food  con- 
stituents which  it  contains,  but  because  it  increases  their 
absorbing  and  retaining  power.  Humus  will  absorb  and 
retain  more  moisture  than  any  other  ingredient  of  soils. 
Clay  soils  are  improved  by  it,  however,  on  account  of  its 
property  of  loosening  and  aerating  them. 

The  four  principal  _mgredie.nls-of -  soils  are  useful,  there- 
fore, not  altogether  because  they  furnish  plant-food,  but 
because  they  give  to  soils  certain  physical  properties 
which  enable  them  to  retain  heat,  moisture,  and  plant- 
food.     These  properties  give  to  soils  what  is  called  phys- 


26  FIRST  PRINCIPLES  OF  AGRICULTURE. 

ical  character,  which  is  very  important  in  determining 
fertility. 

Sandy  Soils.  —  Land  which  contains  over  seventy  per 
cent  of  sand  is  called  sandy.  Such  soils  are  not  only 
poor  in  plant-food,  but  they  can  absorb  and  retain  but 
little  moisture.  The  soil,  loosely  held  together,  permits 
the  rapid  passage  of  water,  and  the  stony  particles  readily 
absorb  heat.  In  hot,  dry  seasons,  the  crops  are  soon 
parched;  in  wet  seasons,  however,  these  same  properties 
enable  the  soil  to  dry  quickly,  thus  permitting,  if  suffi- 
cient food  is  provided,  the  growth  of  maximum  crops, 
when  they  would  be  destroyed  from  excess  of  mois- 
ture on  soils  of  a  more  dense  or  tenacious  character. 
Sandy  soils  are  easy  to  work,  and  may  be  cultivated 
when  quite  wet  without  injury,  and  are  well  adapted 
to  quick-growing  crops;  when  overlying  clay  subsoils, 
they  are  susceptible  of  a  high  degree  of  fertility. 

Clay  Soils.  —  A  clay  soil  is  one  which  contains  over 
fifty  per  cent  of  clay.  A  clay  soil  is  almost  the  reverse 
of  a  sandy  soil.  The  finely  divided  particles  adhere  so 
closely  as  to  make  the  access  of  air,  moisture,  and 
warmth,  difficult;  they  are,  therefore,  called  cold  and 
tenacious.  They  are  hard  to  work,  and,  unless  well 
drained,  crops  are  liable  to  suffer  both  in  wet  and  dry 
seasons ;  in  wet  seasons  because  the  moisture  is  not  freely 
movable,  and  in  dry  seasons  because  the  land  becomes 
so  hard  as  to  prevent  the  penetration  of  roots.  They 
are  well  adapted  to  the  growth  of  cereals  and  grasses. 

Limestone  Soils.  —  The  term  "  lime  "  or  "  calcareous," 
is  applied  to  a  soil  when  it  contains  over  twenty,  per 
cent  of  lime.      Limy   soils  are  usually  of  a  good  char- 


ORIGIN  AND  FORMATION  OF  SOILS.  27 

acter,  are  easy  to  work,  and  well  adapted  to  cereals  or 
fruit. 

Peaty  or  Vegetable  Soils.  —  A  peaty  or  vegetable 
soil  consists  almost  entirely  of  vegetable  matter,  more 
or  less  decayed.  Such  soils  are  very  productive  if  well 
drained,  and  furnished  with  a  sufficiency  of  the  mineral 
constituents. 

Soils,  however,  which  are  best  adapted  to  the  purpose 
of  farming  do  not  belong  strictly  to  either  of  these 
classes,  but  are  rather  those  which  contain  more  even 
proportions  of  the  ingredients ;  hence,  a  further  division 
of  soils  is  usually  made,  based  upon  the  relative  propor- 
tions of  the  principal  ingredients,  sand  and  clay. 

Loamy  Soils.  —  A  soil  consisting  of  a  mixture  of 
sand  and  clay  is  called  a  loam;  if  it  contains  from  ten 
to_twgnty  pjer^cent of^day,  it  is  a  sandy  loam;  if  from 
twenty  to  thirty  per  cent  of  clay,  it  is  a  loam;  if  from 
thirty  to  fifty  per  cent  of  clay,  a  jjlay^JLoam.  Gravelly 
or  limy  loams  are  those  in  which  gravel  or  coarse  sand 
and  lime  are  contained  in  considerable  amounts.  Loams 
are  suitable  for  most  purposes,  and  soils  of  the  different 
natural  classes  are  improved  as  they  approach  the  char- 
acter of  loams. 

It  would  be  impossible  to  describe  and  classify  the 
almost  infinite  variety  of  soils  which  exist  in  nature,  and 
which  are  made  up  from  different  proportions  of  the 
four  ingredients  mentioned. 

Perfect  Soil.  —  A  perfect  soil  is  one  which  contains 
the  ingredients  in  perfect  proportions :  sand,  to  enable  it 
to  absorb  air  and  moisture  in  proper  amounts,  and  to 
render  it  warm  and  friable ;  clay,  to  keep  it  cool,  and 


28  FIRST  PRINCIPLES   OF  AGRICULTURE. 

prevent  a  too  rapid  leaching  or  evaporation  of  water ; 
lirne^  to  assist  in  the  decay  of  vegetable  matter ;  and 
humus,  to  retain  the  best  amount  of  moisture,  and  to 
furnish  material  for  the  various  chemical  processes  con- 
tinually going  on  in  good  soils. 

These  conditions  are  rare,  and  seldom  occur  in  nature, 
though  it  is  in  the  power  of  man  to  produce  them:  still, 
perfect  soils  are  not  to  be  had  without  a  great  deal  of 
labor  and  care ;  and  frequently  it  is  more  important  for 
the  farmer  to  adapt  himself  to  his  soil,  and  make  it 
produce  the  best  which,  from  its  natural  character,  it  is 
best  capable  of  doing,  than  to  attempt  to  change  its 
character.  He  should  not  attempt  to  raise  wheat  when 
the  soil  is  peculiarly  fitted  to  grow  early  vegetables  or 
fruits,  nor  to  grow  early  vegetables  on  soils  only  adapted 
for  the  grasses. 


COMPOSITION  OF  SOILS.  29 


CHAPTER   III. 
Composition  of  Soils. 

A  soil,  like  a  plant,  consists  of  two  distinct  classes 
of  substances,  —  first,  organic  or  vggetable,  derived,  as  we 
have  seen,  from  decaying  growths ;  second,  inorganic  or 
mineral  constituents,  derived  from  the  rocks  which  form 
the  earth's  surface. 

Organic  Substances.  —  Organic  substances  are  made 
up  of  carbon,  oxygen,  hydrogen,  and  nitrogen.  Of  these 
the  nitrogen  is  of  the  most  direct  importance  in  the 
growth  of  the  plant,  and  is  the  valuable  constituent  of 
the  humus  already  described. 

Inorganic  Substances.  —  The  inorganic  or  mineral 
substances  of  the  soil  are  also  identical  with  the  sub- 
stance of  the  ash  of  plants  (with  the  addition  of  alu- 
mina, which  is  not  taken  up  by  the  latter),  namely, 
silica,  alumina,  lime,  potash,  magnesia,  phosphoric  acid, 
soda,  iron,  chlorine,  and  sulphuric  acid.  The  first  three 
of  these,  as  has  already  been  noted,  are  the  principal 
ingredients  of  soils,  and  give  to  them  their  distinctive 
character;  with  the  exception  of  lime,  they  do  not  aid 
materially  in  furnishing  food.  The  more  important  con- 
stituents are  phosphoric  acid  and  potash. 

Phosphoric  Acid. — Phosphoric  acid  is  an  ingredient 
of  all  fertile  soils,  but  is  contained  in  very  small  quan- 


30  FIRST  PRINCIPLES  OF  AGRICULTURE. 

tities  as  compared  with  other  constituents.  Its  most 
common  combination  is  with  lime,  though  it  is  frequently 
found  in  combination  with  iron  and  aluminum.  Bocks 
which  contain  "fossils,"  or  fossiliferous  rocks,  frequently 
contain  high  percentages  of  phosphoric  acid. 

Potash.  —  Potash  is  also  derived .  from  rocks,  and 
varies  in  the  amount  contained  in  different  soils.  Those 
derived  directly  from  granite  or  trap  are  the  richest  in 
this  element;  it  exists  in  the  soil  in  combination  with 
silica,  forming  substances  called  "  silicates,"  which  are 
of  great  importance. 

Lime.  —  Lime  is  an  ingredient  of  most  soils,  and  is 
derived  from  the  decay  of  limestone,  or  from  fossils. 

The  Natural  Fertility  of  Soils.  —  The  mineral  con- 
stituents, phosphoric  acid  and  potash,  though  contained 
in  soils  in  relatively  small  amounts,  ranging  from  less 
than  one-tenth  per  cent  to  over  one  per  cent,  give  to 
soils  their  chief  claims  to  natural  fertility;  since  most 
agricultural  plants  require  relatively  large  proportions 
of  these  in  proportion  to  other  mineral  constituents. 

The  quantity  of  phosphoric  acid  and  potash  contained 
in  a  soil  is,  however,  comparatively  great,  since  the  sur- 
face soil  at  a  depth  of  nine  inches  will  weigh,  when  per- 
fectly dry,  three  to  three  and  one-half  million  pounds 
per  acre ;  hence,  with  even  one-tenth  per  cent,  it  would 
contain  from  three  thousand  to  three  thousand  five  hun- 
dred pounds  of  each  of  these  constituents. 

The  other  necessary  mineral  ingredients  are  found  in 
greater  or  less,  and  usually  in  sufficient  amounts  in  all 
soils.  These,  while  all  essential  to  the  complete  develop- 
ment of  the  plant,  are  of  course  less  liable  to  exhaustion. 


COMPOSITION  OF  SOILS.  31 

The  immediate  fertility  of  a  soil  depends,  however, 
not  so  much  upon  the  quantity  of  the  constituents  con- 
tained in  it  as  upon  the  amount  of  each  that  may  be 
available  to  the  plant. 

Analysis  of  Soils.  —  The  composition  of  a  rich  wheat 
soil  and  of  a  wheat  plant,  as  shown  by  analysis,  in 
the  diagrams1  (page  32),  indicates  the  relation  of  the 
composition  of  the  plant  to  the  composition  of  the  soil. 

The  chemical  analysis  of  a  soil  shows  the  percentages 
of  the  different  constituents  contained  in  it.  It  is  ob- 
served that  the  constituents  which  the  soil  possesses 
to  only  a  limited  extent  are  contained  in  the  plant  in 
relatively  large  amounts;  these  are,  therefore,  termed 
essential  plant-food  constituents,  because  of  their  greater 
liability  to  exhaustion. 

Weight  of  Soils.  —  In  studying  a  soil  from  a  state- 
ment of  its  analysis,  regard  must  be  had  to  the  weight 
of  soils.  The  constituents  of  the  analysis  are  expressed 
in  per  cent  or  pounds  per  hundred ;  it  is  evident,  there- 
fore, that  a  soil  weighing  one  hundred  pounds  per  cubic 
foot,  and  containing  four-tenths  of  a  per  cent  of  phos- 
phoric acid,  would  contain  a  much  greater  amount  of 
phosphoric  acid  per  acre  than  a  soil  showing  the  same 
percentage,  but  weighing  fifty  pounds  per  cubic  foot. 

It  is  estimated  that  dry  sand  weighs  from  one  hun- 
dred to  one  hundred  and  twenty  pounds  per  cubic  foot; 
loam,  from  ninety  to  one  hundred  pounds ;  clay,  seventy 
to  eighty  pounds ;  and  peat,  thirty  to  fifty  pounds.  An 
analysis,  therefore,  which  shows  the  same  per  cent 
of    the  constituents    in   one    soil    may  not  indicate   its 

*  Adapted  from  Villo. 


32 


FIRST  PRINCIPLES   OF  AGRICULTURE. 


Composition  of  Rich  Wheat  Soil. 


POUNDS    PEE   HUNDRED. 


Carbon. 

Hydrogen 

Oxygen. 


12.67 


Silica 71.55^ 

Alumina ....    6.94 

Iron 5.17 

Magnesia      .    .    .    1.08 

Soda 0.43 

Sulphuric  Acid    .    0.04 
85.21 


Elements  which,  though  essential,  are  abun- 
dantly supplied  by  the  air  and  water. 


Elements  which  are  either  non-essential  oi 
are  required  by  the  plant  in  minimum 
amounts. 


.    0.121 
.    0.43 


Nitrogen  . 

Phosphoric  Acid  .    0.43  I  Elements  absolutely  essential,  of  which  rela. 

Potash      ....    0.35  [      tively  large  amounts  are  required. 

Lime 1.22; 

2.12 


Composition  of  Wheat  Plant. 

POUNDS  PER  HUNDRED. 


Carbon     ....  47.69 

Hydrogen     .    .    .    5.54 

Oxygen    ....  40.32 

93.55 

Soda    .....  0.09" 

Magnesia      .    .    .  0.20 

Sulphuric  Acid     .  0.31 

Chlorine  ....  0.04 

Iron 0.06 

Silica 2.75 

3.45' 

Nitrogen  .  .  .  .  1.60] 
Phosphoric  Acid  .  0.45  I 
Potash      ....    0.661 

Lime 0.29J 

3.00 


These  are  derived  from  the  air  and  rain. 


These  are  abundantly  provided  by  the  soil, 
and  it  is  unnecessary  to  add  them  in  any 
case. 


These  the  soil  possesses  only  to  a  limited  ex- 
tent, and  the  deficiency  must  be  supplied. 


COMPOSITION  OF  SOILS.  33 

true  character  in  reference  to  the  amount  of  plant-food 
contained  in  it,  unless  it  is  accompanied  by  a  descrip- 
tion of  its  general  character,  whether  sandy,  clayey,  or 
peaty. 

It  will  be  observed  from  the  foregoing,  too,  that  the 
ordinary  idea  of  the  weight  of  soil  has  reference  to  the 
physical  character,  rather  than  actual  weight.  A  sandy 
soil  is  called  "  light,"  and  a  clay  soil  "  heavy ; "  while  in 
reality  a  sandy  soil  is  heavy,  and  a  clay  soil  is  light. 

The  sandy  soil  is  called  light  because  it  is  easier  to 
work,  —  the  particles  of  sand  are  readily  separated  from 
each  other,  and  no  particular  force  is  required ;  while  in 
the  case  of  clay  soils  the  particles  adhere  tenaciously,  and 
it  requires  considerable  force  to  separate  them. 

Classes  of  Soil  Constituents.  —  The  constituents  of 
a  soil  may  again  be  divided  into  three  classes,  —  first, 
those  which  serve  mainly  as  a  mechanical  support  for  the 
plants,  like  sand,  clay,  limestone,  and  gravel ;  second, 
dormant  or  reserve  substances,  which  not  only  act  the 
same  as  the  first  class,  but  are  capable  of  changing  to 
such  a  form  as  to  furnish  nutrition  to  the  plant;  these 
are  of  both  vegetable  and  mineral  origin;  and  third, 
active  constituents,  or  those  directly  available  to  plants. 

The  mechanical  constituents  constitute  the  bulk  of  all 
soils — frequently  over  ninety-five  per  cent.  The  second 
class,  or  dormant,  are  contained  in  most  soils  in  rela- 
tively small  amounts  as  compared  with  the  first  class, 
though  the  quantity  that  a  soil  may  contain  varies  con- 
siderably, depending  upon  its  formation. 

The  active  constituents,  those  that  are  immediately 
available  to  the  plant,   are   never   present  in   even   the 


84  FIRST  PRINCIPLES  OF  AGRICULTURE. 

best  soils  in  large  amounts ;  they  are  formed  slowly  from 
those  that  are  dormant.  Humus  is  not  a  direct  food, 
but  is  capable  of  being  changed  into  food. 

Clay  and  substances  containing  phosphoric  acid,  by 
weathering,  or  the  action  of  frost,  heat,  and  moisture, 
are  changed  to  such  an  extent  as  to  give  up,  in  time, 
portions  of  their  potash,  phosphoric  acid,  and  lime. 

The  True  Measure  of  Fertility.  —  The  active  constit- 
uents, however,  measure  the  true  fertility  of  any  soil. 
The  dormant  substances  may  be  rich  in  phosphates,  pot- 
ash, lime,  and  humus,  and  yet  it  may  be  impossible  to 
produce  a  single  plant  from  them,  because  the  surround- 
ing conditions  are  never  favorable  for  the  activities  that 
cause  their  change  into  active  substances. 

An  analysis  of  the  soil  does  not  show  true  fertility, 
unless  it  shows  how  much  of  the  total  constituents  of 
the  soil  are  capable  of  being  made  active,  and  thus 
useful  to  the  crops :  it  simply  shows  the  possibilities 
that  are  lying  dormant. 

One  Element  Cannot  Substitute  Another.  —  An- 
other point  is  also  important  in  this  connection ;  namely, 
that,  of  the  three  active  constituents,  nitrogen,  phos- 
phoric acid,  and  potash,  which  exist  in  small  quantities 
in  all  soils,  the  one  contained  in  minimum  amounts  in 
the  soil  determines  its  power  of  producing  plants;  that 
is,  the  crop  cannot  rise  above  the  point  measured  by 
the  element  existing  in  the  smallest  amount  —  one  ele- 
ment cannot  be  substituted  for  another.  For  example, 
if  we  have  in  an  acre  of  soil  only  sufficient  nitrogen  for 
ten  bushels  of  wheat,  the  crop  could  not  be  increased 
to  any  considerable  extent  beyond  that  point,  even  though 


COMPOSITION  OF  SOILS.  35 

phosphoric  acid  and  potash  were  contained  in  unlimited 
quantities ;  a  balance  of  the  plant-food  constituents  is 
essential  to  full  and  complete  growth  and  development. 

Exhaustion  of  Soils.  —  Exhaustion  of  soils  has  refer- 
ence mainly  to  the  four  constituents,  nitrogen,  phosphoric 
acid,  potash,  and  lime ;  the  amount  of  the  others  is  usually 
contained  in  excessive  quantities  in  all  soils.  Exhaustion 
is,  however,  a  relative  matter,  since  it  is  not  possible 
to  completely  exhaust  a  soil  of  its  active  constituents. 
Exhaustion  means  properly  the  reducing  of  the  constit- 
uents to  that  point  which  makes  the  production  of  crops 
unprofitable;  hence  the  question  of  exhaustion  is  a  vari- 
able one,  determined  in  a  large  measure  by  local  circum- 
stances. 

Exhaustion,  too,  may  have  reference  to  one  constituent 
only;  for  instance,  there  may  be  an  abundance  of  nitro- 
gen and  phosphoric  acid,  and  a  deficiency  of  potash. 
By  growing  a  class  of  crops  which  take  more  of  the 
constituents  that  are  present  in  relatively  large  amounts, 
and  less  of  those  that  exist  in  small  amounts,  the  period 
of  exhaustion  is  deferred. 

Natural  Strength  of  Soils.  —  The  power  which  soils 
possess  of  gradually  forming  active  ingredients  is  termed 
natural  strength.  It  is  obvious  that  the  character  and 
origin  of  the  soil  have  an  important  bearing  upon  this 
point. 

The  natural  strength  of  a  light  sandy  soil  may  be 
measured  by  a  crop  of  wheat  of  five  bushels  per  acre; 
while  the  natural  strength  of  rich  valley  or  prairie  soil 
may  be  measured  by  an  annual  yield  of  twenty-five 
bushels  of  wheat   per  acre;  that  is,  in  the  one  case,  the 


36  FIRST  PRINCIPLES  OF  AGRICULTURE. 

substances  which  form  the  soil  are  of  such  a  character 
as  to  permit  of  the  change  of  but  a  small  proportion  of 
its  dormant  into  active  constituents,  while,  in  the  other, 
a  large  proportion  of  the  constituents  are  annually  ren- 
dered available. 

Soils  overlying  limestone  and  granite,  and  those  formed 
by  the  gradual  accumulation  of  vegetable  matter,  as  in 
the  prairies  of  the  Western  States,  possess  a  high  natu- 
ral strength.  They  contain  large  quantities  of  the  dor- 
mant constituents,  which  are  of  such  a  character  as  to 
be  readily  changed  into  activity  under  ordinary  condi- 
tions of  season  and  farm  practice,  and  large  crops  are 
possible  each  year  for  a  long  period. 

Sandy  soils,  perhaps,  are  the  best  examples  of  soils  of 
low  natural  strength ;  in  these  the  purely  mechanical  con- 
stituents are  in  great  excess,  no  considerable  quantity  of 
dormant  or  reserve  substances  exist,  and  the  constituents 
made  active  are  only  sufficient  for  minimum  annual  yields. 

Texture  of  Soils.  —  Another  point  to  be  taken  into 
consideration,  when  studying  the  composition  of  a  soil, 
is  the  power  it  possesses  of  absorbing  and  retaining  such 
constituents  as  may  become  active.  This  characteristic 
of  a  soil  is  termed  its  "  texture ; "  and  it  has  not  only  a 
bearing  upon  the  adaptability  of  the  soil  to  the  growth 
of  plants,  but  also  exercises  a  decided  influence  upon 
such  growth. 

Soil  so  open  in  texture  as  to  freely  admit  the  circula- 
tion of  water  is  more  liable  to  be  depleted  in  its  active 
constituents  than  a  soil  which  is  close  in  texture,  and 
retains  for  a  considerable  time  the  water  which  falls 
upon  it. 


COMPOSITION  OF  SOILS.  37 

The  nature  of  the  subsoil  is  also  an  important  consid- 
eration. If  the  soil  rests  immediately  upon  a  rock,  or 
upon  sand,  it  will  be  found  to  dry  out  much  more  rapidly 
than  if  it  rests  upon  a  clay  subsoil.  In  the  first  place,  the 
water  passes  rapidly  beyond  the  reach  of  the  roots,  and 
cannot  readily  get  back ;  in  the  second  place,  it  does  not 
percolate  so  rapidly,  while  at  the  same  time  it  retains  its 
connection  with  the  surface. 

This  point  is  very  apparent  to  one  who  has  observed 
the  red  shale  soils  in  central  New  Jersey.  They  are 
reasonably  rich  in  all  forms  of  plant-food,  yet  those  which 
lie  directly  upon  the  shale  or  rock  are  much  less  pro- 
ductive than  those  which  lie  upon  a  clayey  subsoil.  The 
shale  permits  a  too  free  escape  of  water,  and  crops  suffer 
more  severely  from  drouth  than  those  which  lie  upon  a 
clayey  subsoil.  It  is  essential  that  water  be  freely  mova- 
ble in  soils,  in  order  to  properly  prepare  the  food,  as  well 
as  to  carry  it  to  the  roots  of  plants,  but  it  must  be  freely 
movable  in  all  directions. 

Climate.  —  The  climate  is  also  a  matter  of  importance  : 
rainfall,  temperature,  location,  all  exert  an  influence  in 
determining  the  value  of  a  soil,  and  should  be  taken  into 
consideration  in  connection  with  its  chemical  composition. 

The  average  rainfall  may  be  sufficient;  but  if  it  is  not 
properly  distributed  throughout  the  growing  season,  nor- 
mal growth  is  impossible.  The  same  is  true  of  tempera- 
ture ;  cold  in  harvest  time  is  ruinous,  though  the  normal 
temperature  for  the  year  may  have  been  attained. 

Loss  and  Gain  to  Soil.  —  A  soil,  whether  cultivated 
or  not,  is  continually  changing,  the  various  causes  which 
combine  to  form  soils  being  ever  at  work  to  make  them 


38  FIRST  PRINCIPLES  OF  AGRICULTURE. 

richer  or  poorer.  If  left  to  themselves,  the  constituents 
rendered  soluble  by  air,  moisture,  and  chemical  action, 
as  well  as  the  finer  particles  of  earth,  are  carried  by 
rains  in  greater  or  less  amounts  into  the  streams  and 
brooks.  Certain  of  the  soil  constituents  are,  however, 
less  liable  to  be  lost  through  drainage  than  others;  that 
is,  soils  do  not  exert  the  same  retentive  power  for  all 
constituents. 

The  constituents  of  the  greatest  interest  to  the  farmer 
are  nitrogen,  phosphoric  acid,  potash,  and  lime.  Of 
these,  nitrogen  and  lime  form  certain  compounds  that 
are  extremely  soluble  and  freely  movable  in  the  soil ; 
drainage  waters  are  seldom  free  from  traces  of  nitrates, 
and  of  chlorides  of  sodium  and  calcium  (lime). 

On  the  other  hand,  ammonia,  a  compound  containing 
nitrogen,  and  phosphoric  acid  and  potash  are  seldom  found 
under  natural  conditions  in  any  considerable  amounts  in 
drainage  waters.  For  these  the  soil  possesses  a  strong 
retentive  power,  though  they  are  not  held  so  strongly  as 
to  be  unavailable  to  plants. 

This  power  of  soils  is  not  only  important  in  showing 
the  probable  loss  or  gain  of  fertility  in  uncultivated  soils, 
but  has  a  wide  bearing  upon  their  possible  improvement. 
Phosphoric  acid  and  potash  particularly,  when  added  to 
soils,  are  fixed,  and  remain  until  removed  by  the  plants. 

Clay,  humus,  and  lime  are  the  ingredients  in  soils 
which  exert  the  greatest  influence  in  retaining  the  solu- 
ble phosphates,  potash  salts,  and  ammonia  compounds. 

Absorptive  Properties  of  Soils.  —  The  property 
which  a  soil  possesses  of  breaking  up  such  compounds, 
and  holding  fast  to  the  essential  elements,  is  both  physi- 


COMPOSITION  OF  SOILS.  ,  39 

cal  and  chemical.  The  holding  of  such  bases  as  potash, 
lime,  etc.,  is  due  to  the  presence  in  the  soil  of  -what  are 
termed  simple  silicates;  these  are  capable  of  combining 
with  other  silicates  to  form  double  silicates.  A  silicate 
of  alumina,  for  instance,  will  combine  with  a  silicate 
of  ammonia  to  form  a  double  silicate  of  alumina  and 
ammonia.  All  soils  possess  this  absorbing  power  in 
some  degree,  though  it  belongs  particularly  to  soils  con- 
taining clay. 

Soils  do  not,  however,  possess  an  equal  absorbing  power 
for  acids.  Nitric  acid  is  not  absorbed,  but  is  freely 
movable.  The  only  acid  of  importance  absorbed  by  the 
soil  is  phosphoric  acid,  which  combines  with  lime,  iron, 
and  alumina,  forming  phosphates,  —  compounds  of  great 
importance  in  plant  nutrition,  which  are  not  removed 
from  the  soil  except  through  the  growth  of  plants. 

This  absorbing  property  of  soils  may  be  nicely  illus- 
trated by  filling  a  cylinder  of  suitable  length  with  a  good 
soil,  and  pouring  upon  it  a  dilute  solution  containing 
one  or  more  bases,  including  potash  and  lime,  and  both 
nitric  and  phosphoric  acid.  An  examination  of  the  solu- 
tion which  passes  through  will  show  the  presence  of  nitric 
acid,  and  an  absence,  at  least  in  any  amount,  of  the  potash 
and  phosphoric  acid.  Good  soils  fix  all  of  the  essential 
constituents,  except  nitrogen  when  it  is  in  the  form  of  a 
nitrate. 

The  farmer  can  reduce  the  losses  due  to  drainage  by 
careful  management.  The  drainage  waters  contain  least 
nitrates  when  crops  are  growing  and  well  cultivated. 
This  carrying  away  of  plant-food  constituents  by  the  rain 
into  the  drains  may  be  regarded,  therefore,  as  a  natural 


40  FJRST  PRINCIPLES  OF  AGRICULTURE. 

loss  to  soils,  and  is  greater  or  less  according  to  the  char- 
acter of  the  soil,  and  the  treatment  it  receives.  On  the 
other  hand,  there  is  a  gain  in  the  fertility  of  soils  due 
to  natural  causes. 

Bain  carries  to  the  soil  appreciable  amounts  of  nitric 
acid  and  ammonia,  as  well  as  certain  solid  substances, 
existing  in  the  atmosphere.  The  gain  from  this  source 
is  greatest  in  the  vicinity  of  cities,  and  least  in  the  open 
country.  The  gain  due  to  the  action  of  water,  heat,  cold, 
and  decaying  vegetable  matter  has  already  been  referred 
to  in  previous  sections,  though  the  changes  taking  place 
in  vegetable  matter  require  further  notice. 

Nitrification.  —  Vegetable  matter  is  the  source  of 
humus  of  soils,  and  the  active  principle  of  humus  is 
nitrogen.  The  nitrogen  in  humus  is  combined  with  car- 
bon, and  in  this  form  it  is  not  available  to  plants.  In 
order  to  become  most  useful  to  them  it  must  be  changed 
into  a  nitrate,  since  plants  take  up  their  nitrogen  chiefly 
in  this  form.  This  process  is  called  "nitrification,"  and 
is  caused  by  minute  "organisms"  or  "ferments,"  which 
are  present  in  all  fertile  soils. 

These  ferments  are  most  active  in  warm,  moist,  well- 
drained  soils,  when  nitrification  proceeds  rapidly;  they 
are  not  active  when  the  temperature  is  lower  than  41°  F. 
or  higher  than  131°  F.  In  winter,  in  temperate  climates, 
nitrification  practically  ceases  altogether,  while  in  sum- 
mer it  proceeds  most  rapidly.  As  soon  as  nitric  acid  is 
formed  by  this  process,  it  immediately  combines  with 
some  base,  preferably  lime ;  hence,  if  drainage  is  allowed, 
the  loss  of  nitrates  is  always  accompanied  by  a  loss  of 
lime. 


THE  IMPROVEMENT  OF  SOILS.  41 


CHAPTER  IV. 
The  Improvement  of  Soils. 

The  improvement  of  soils  may  be  regarded  as  of  two 
kinds,  —  first  physical,  and  second  chemical ;  though  this 
classification  is  not  always  well  defined.  Frequently  an 
improvement  in  the  physical  character  of  soils  is  also 
accompanied  by  important  chemical  changes.  The  im- 
provement of  soils  due  to  natural  causes,  while  consider- 
able in  the  aggregate,  is  insignificant,  in  point  of  time, 
compared  with  that  which  may  be  secured  by  the  farmer 
through  artificial  means.  The  true  aim  of  the  farmer 
should  be  to  bring  the  soil  into  a  condition  to  produce 
crops  which  are  well  adapted  to  his  location,  and  which 
are  as  large  as  the  average  conditions  of  climate  and 
season  will  permit. 

The  first  point  to  determine  is  whether  the  land  is 
worth  improving  ;  the  kind  of  crops  that  can  be  raised,  and 
their  probable  market  value,  must  guide  in  this  respect. 

Physical  Imperfection.  —  One  of  the  chief  imperfec- 
tions in  natural  soils,  aside  from  their  chemical  character, 
is  in  respect  to  water ;  they  contain  too  much  or  too 
little.  If  too  much,  the  imperfections  may  be  in  many 
cases  corrected  by  proper  drainage  ;  if  too  little,  by 
adding  water  or  such  materials  as  may  increase  the 
absorbing  and  retaining  power  of  soil  for  water. 


42  FIRST  PRINCIPLES  OF  AGRICULTURE. 

The  earth  may  be  compared  to  a  sponge  full  of  water, 
which  rises  towards  the  surface  with  heavy  rainfalls,  and 
falls  below  as  evaporation  and  percolation  proceed. 

Drainage.  —  If  a  hole  dug  into  the  soil  partly  fills 
with  water,  and  remains  with  slight  fluctuations  through 
the  season,  the  water  contained  in  it  is  called  "bottom 
water,"  and  the  point  to  which  it  rises  is  called  the 
"water  level."  If  the  water  level  is  constantly  near 
the  surface,  the  soil  is  liable  to  be  too  wet ;  for  most 
plants  suffer  if  their  roots  are  immersed  for  any  length 
of  time  in  stagnant  water.  Plants  need  air,  both  for 
root  and  branch.  Too  much  water  in  a  soil  prevents 
the  circulation  of  air,  and  also  keeps  it  too  cold  for 
most  crops  ;  the  cranberry  and  rice  plants  are  prominent 
exceptions  to  this  rule.  The  soil  may  also  be  too  wet, 
even  when  the  water  level  is  deep  into  the  earth,  by 
reason  of  absorbing  too  much  of  the  rain  that  falls  upon 
it.  Drainage  corrects  in  the  first  case  by  lowering  the 
water  level,  and  in  the  second  by  permitting  a  more 
rapid  passage  of  water  through  the  soil. 

Land  well  drained  is  improved,  not  only  by  the  removal 
of  water  from  it,  but  because  the  more  rapid  diffusion 
and  passage  of  the  water  through  the  soil  carry  the  air 
and  warmth  to  lower  levels,  which  are,  as  has  already 
been  shown,  important  factors  in  making  soil  constitu- 
ents soluble,  and  thus  increasing  the  power  of  plants 
to  secure  food. 

In  too  many  cases  half-developed  crops  are  secured 
year  after  year  upon  land,  which,  if  properly  drained, 
would  be  capable  of  maximum  production.  Where  springs 
occur,  and  where  the  land  is  composed  of  clay  overlying 


THE  IMPROVEMENT  OF  SOILS.  43 

clay  subsoils,  drainage  usually  results  in  great  improve- 
ment and  profit  to  the  owner. 

Methods  of  Drainage.  —  The  efficiency  of  drains  de- 
pends upon  the  free  passage  of  water  through  them.  They 
should  always  lead  to  the  lowest  portion  of  the  field ;  if 
the  land  is  level,  they  must  be  gradually  sloped  —  one 
foot  in  five  hundred  will  furnish  sufficient  grade  for  the 
flow  of  water.  On  a  slope,  the  drains  may  be  laid  at  a 
uniform  depth  from  the  surface ;  the  main  drain  should 
always  occupy  the  lowest  part  of  the  field. 

The  depth  of  drains  and  their  distance  from  each  other 
are  governed  by  the  character  of  the  land.  On  light,  open 
soils,  they  should  be  deeper  and  farther  apart;  on  heavy 
land  they  should  be  nearer  to  the  surface  and  to  one 
another.  The  mouth  of  the  drain  should  be  well  pro- 
tected, and  kept  free  from  all  obstructions. 

Irrigation.  —  When  lands  contain  too  little  water  irri- 
gation is  frequently  resorted  to,  though  the  best  results 
from  irrigation  are  attained  on  well-drained  land.  Irri- 
gation not  only  softens  the  land,  thus  making  it  more 
permeable  for  the  roots  of  plants,  but  it  is  effective  in 
dissolving  the  dormant  constituents  of  soils.  Large  tracts 
of  now  barren  land  in  the  United  States  only  require  water 
to  make  them  fruitful. 

The  advantages  of  irrigation  are,  perhaps,  most  con- 
spicuous in  the  States  of  Colorado  and  California.  In 
portions  of  the  Eastern  States  crops  are  frequently  ruined 
by  a  lack  of  water  at  the  right  time ;  the  irrigation  of 
these  areas  is  only  a  question  of  time. 

Claying  and  Sanding.  —  Further  imperfections  in 
the  physical  character  of  natural  soils  are  also  common. 


44  FIRST  PRINCIPLES  OF  AGRICULTURE. 

Sandy  soils  are  improved  when  made  more  compact  and 
tenacious;  this  may  be  accomplished  by  adding  clay,  or 
organic  matter,  or  both.  Clay  soils  are  improved  as  they 
are  made  more  porous  and  open;  this  may  be  accom- 
plished, in  part  at  least,  by  the  addition  of  sand.  Clay- 
ing and  sanding  are  expensive  processes,  and  are  seldom 
resorted  to  in  this  country  except  in  cranberry  culture ; 
though  in  districts  where  clay  marls  are  abundant,  the 
same  object  is  accomplished  by  the  application  of  this 
material.  Marling,  however,  materially  improves  their 
chemical  character,  because  of  the  mineral  constituents, 
potash,  phosphoric  acid,  and  lime,  one  or  all  of  which 
may  be  contained  in  them. 

Green  Manuring.  —  The  addition  of  organic  vegetable 
matter  to  soils,  for  the  purpose  of  improving  both  their 
physical  and  chemical  character,  is  readily  accomplished 
by  means  of  green  manuring.  The  term  "  green  manur- 
ing "  is  used  when  the  crops  themselves  are  plowed  under 
in  their  green  state.  Any  plant,  of  course,  may  serve  for 
this  purpose,  though  those  most  commonly  used  are  red 
and  crimson  clover,  cow  pea,  rye,  and  buckwheat. 

Plants  most  Useful.  —  Of  these  crops  the  clovers  and 
peas  are  more  useful  than  the  others.  Clovers,  peas, 
beans,  lupins,  vetches,  and  a  number  of  others  of  less 
importance,  belong  to  a  class  of  plants  called  "legumes," 
which  have  the  power  of  securing  nitrogen  from  the  air, 
and  can,  therefore,  make  perfect  growth  under  proper 
conditions  without  depending  upon  soil  nitrogen.  This 
function  of  the  legumes  has  long  been  known  by  practi- 
cal farmers,  but  the  method  by  which  the  nitrogen  is 
obtained  is  a  quite  recent  discovery. 


THE  IMPROVEMENT  OF  SOILS.  45 

These  plants  have  small,  knotty  growths,  called  "tuber- 
cles," on  their  roots,  which  are  believed  to  be  caused 
directly  or  indirectly  by  certain  bacteria  which  are  present 
in  soils  in  which  this  class  of  plants  are  grown.  Recent 
experiments  have  shown,  too,  that  soils  which  do  not 
contain  these  bacteria  may  be  inoculated  by  applying  a 
light  dressing  of  soil  from  a  field  in  which  the  plants  have 
previously  grown  to  perfection,  without  direct  applications 
of  nitrogenous  material.  It  is  through  these  tubercles  that 
the  plants  are  supposed  to  gain  free  nitrogen  from  the 
atmosphere.  Experiments  have  shown  pretty  clearly  that, 
where  they  have  been  formed,  the  nitrogen  in  the  crop  is 
far  greater  than  when  they  are  absent.  The  fact  that 
such  is  the  case  is  sufficient  for  us  to  make  use  of  this 
free  source  of  the  expensive  element,  nitrogen;  and  it 
makes  green  manuring  with  these  plants  a  most  impor- 
tant part  of  farm  work,  not  only  as  a  means  of  securing 
nitrogen  for  the  crop  itself,  but  as  a  source  of  nitrogen 
for  crops  unable  to  secure  it  except  from  soil  sources. 

An  acre  of  an  average  crop  of  red  or  crimson  clover, 
or  of  cow  peas,  will  contain  one  hundred  and  fifty  pounds 
of  nitrogen,  equivalent  to  that  contained  in  fifteen  tons  of 
average  stable  manure.  Rye  or  buckwheat,  or  other  plants, 
which  do  not  possess  this  power  of  securing  nitrogen,  are 
much  less  valuable  for  this  purpose. 

Green  manuring  is  particularly  useful  in  the  improve- 
ment of  light  lands  usually  deficient  in  humus,  and  in 
that  method  of  farm  practice  where  exhaustive  crops  are 
grown  without  the  addition  of  yard  manure  or  other  forms 
of  organic  matter.  By  the  use  of  the  legumes  as  green 
manures,   and   the   addition   of  materials   furnishing  the 


46  FIRST  PRINCIPLES  OF  AGRICULTURE. 

essential  mineral  constituents,  potash,  phosphoric  acid, 
and  lime,  light  lands  may  be  rapidly  improved  and  made 
very  fertile,  while  lands  used  for  growing  vegetables  or 
fruits  may  be  kept  in  a  high  state  of  cultivation  and 
in  good  mechanical  condition,  without  the  expenditure  of 
money  and  labor  for  stable  manure,  now  regarded  as  so 
essential  by  the  majority  of  farmers. 

Rye  and  Buckwheat  as  Catch  Crops.  —  Eye  and 
buckwheat  are  of  considerable  advantage,  even  though  they 
are  able  to  secure  their  nitrogen  only  from  soil  sources, 
because  their  habits  of  growth  permit  them  to  be  used  as 
catch  crops,  or  those  not  interfering  with  regular  rotations. 

The  addition  of  the  vegetable  carbonaceous  matter 
which  is  contained  in  these  crops  is,  of  course,  quite  as 
advantageous  as  that  contained  in  those  having  the  special 
power  of  securing  nitrogen ;  though  recent  studies  of 
crimson  clover  show  it  to  be  quite  as  well  adapted  for  a 
catch  crop  as  those  already  mentioned,  thus  limiting  the 
usefulness  as  green  manures  of  other  crops  than  the 
clovers   or   legumes. 

Care  in  the  Use  of  Green  Manures.  —  The  turning 
under  of  heavy  crops  of  clover  or  rye  in  the  summer,  when 
the  conditions  are  most  favorable  for  rapid  decay,  namely, 
a  high  temperature,  and  an  abundance  of  moisture,  is  some- 
times followed  by  unfavorable  results.  Whether  this  is 
due  to  the  too  great  development  of  organic  acids  from  the 
rapid  decay  of  vegetable  matter,  as  some  believe,  is  not 
thoroughly  established  ;  though  it  is  known  that  where  the 
soil  contains  sufficient  lime,  or  when  lime  is  added,  the 
danger  in  this  direction  is  very  much  reduced,  or  altogether 
obviated. 


THE  IMPROVEMENT  OF  SOILS.  47 

Green  Manures  add  no  Minerals  to  the  Soil. — It 
is  observed,  from  the  foregoing,  that  the  use  of  green 
manures  can  add  no  minerals  to  the  soil;  nevertheless, 
its  chemical  qualities  are  improved.  In  the  first  place, 
constituents  existing  in  the  soil,  as  well  as  in  the  subsoil, 
have  been  collected  by  the  roots  and  stored  in  the  whole 
plant,  which,  turned  under,  concentrate  these  constituents 
in  the  surface  soil ;  and,  secondly,  the  constituents  con- 
tained in  combination  with  vegetable  matter  are  readily 
given  up  again,  because  of  the  tendency  of  such  sub- 
stances to  decay. 

Improvement  Due  to  Lime.  —  The  addition  of  lime 
also  improves  the  physical  nature  of  soil.  Upon  sandy 
soils  its  effect  is  to  fill  up  the  openings,  which  makes 
them  more  adherent  and  more  retentive  of  moisture,  thus 
absorbing  less  heat  during  the  day,  and  retaining  more 
at  night.  On  clay  soils,  the  effect  of  lime  is  still  more 
important;  the  fine  particles  are  separated,  and  the  soil 
made  more  open,  porous,  and  friable  ;  air  and  water  cir- 
culate more  freely ;  the  soil  is  warmer  and  easier  to  work. 

Tillage. — Natural  soils  are  further  improved  by  til- 
lage. Tillage  includes  the  operations  of  plowing,  culti- 
vating, harrowing,  rolling,  etc.,  the  result  of  which  is  to 
destroy  weeds  and  foreign  growths ;  to  subject  larger 
portions  of  the  soil  to  contact  with  air,  thus  increasing 
the  tendency  to  decay ;  and  to  pulverize  the  surface  soil, 
and  render  it  more  absorptive  and  porous,  and  more  favor- 
able for  the  germination  of  seeds,  and  for  the  penetration 
and  activity  of  the  fine  roots. 

Methods  of  Plowing.  —  The  methods  followed  in 
plowing  vary  with  the    conditions    and    character  of    the 


48  FIRST  PRINCIPLES   OF  AGRICULTURE. 

soil.  It  should  be  deep  enough  to  include  all  of  the 
surface  soil,  and  the  furrow  should  be  turned  in  such  a 
manner  as  to  subject  the  largest  surface  to  the  action  of 
the  air. 

Narrow  furrows  thrown  on  edge  expose  the  greatest 
surface  area  to  the  influence  of  the  atmosphere,  while 
a  wide  furrow,  turned  nearly  flat,  presents  the  least 
exposed  surface.  The  former  method  is  best  adapted 
for  heavy  soils,  rich  in  the  dormant  constituents,  and 
the  latter  more  useful  where  the  object  is  rather  the 
production  of  a  good  tilth  or  seed-bed. 

Proper  plowing  also  greatly  assists  in  surface  drain- 
age. The  distance  between  the  ridges  is  called  a  land,  and 
the  narrower  the  land  the  better  the  drainage.  Where 
the  natural  drainage  is  good,  ridge  plowing  is  not  so 
important.  On  such  lands  level  plowing  is  advisable; 
an  even  surface  possesses  many  advantages  in  the  culti- 
vating and  harvesting  of  crops. 

As  a  rule,  it  is  not  well  to  bring  the  subsoil  to  the 
surface  when  the  planting  of  the  crop  immediately  fol- 
lows the  plowing;  though  on  alluvial  soils  this  practice 
is  often  followed  for  the  purpose  of  deepening  the  sur- 
face soils. 

Fall  Plowing.  —  Fall  plowing  is  useful  in  economiz- 
ing time  in  the  spring,  in  improving  heavy  soils,  and  in 
destroying  many  injurious  insects.  Land  plowed  in  the 
fall  or  very  early  spring  is  also  better  able  to  with- 
stand drouth  than  if  plowed  immediately  preceding  the 
planting  of  the  crop,  particularly  if  the  drouth  occurs  early 
in  the  season. 

The  gradual   deepening   of    the   soil   is    better   accom- 


THE  IMPROVEMENT  OF  SOILS.  49 

plished  on  average  soils  by  deep  fall  plowing;  since  a 
small  quantity  of  subsoil,  then  brought  to  the  surface,  is 
greatly  improved  and  mellowed  by  alternate  freezing  and 
thawing  during  the  winter. 

The  cultivation  and  harrowing  of  the  soil  before  seed- 
ing in  the  spring  should  be  deep  and  thorough ;  all 
clods  should  be  crushed,  and  the  particles  of  soil  made 
as  fine  as  possible;  the  finer  the  soil  is  made  the  more 
food  is  made  available,  and  the  more  moisture  is  re- 
tained. The  seed-bed  should  be  deep,  clean,  and  moist, 
for  the  proper  germination  and  growth  of  plants. 

Subsoil  Plowing.  —  By  subsoil  plowing  is  meant  the 
breaking  up  of  the  subsoil,  without  bringing  it  to  the 
surface ;  this  is  accomplished  by  a  plow  of  special  con- 
struction, following  in  the  furrows  made  by  a  surface 
plow.  Subsoil  plowing  is  of  great  importance  where  the 
subsoil  is  hard  and  compact,  and  improves  the  soil,  by 
making  the  movement  of  water  easier,  by  admitting  the 
free  access  of  air,  and  the  easy  penetration  of  the  roots 
of  plants. 

Capillary  Attraction.  —  Water  escapes  from  the  sur- 
face of  soils  by  means  of  what  is  termed  "capillary  at- 
traction." That  is,  the  interstices,  or  spaces,  between  the 
particles  of  soil  serve  as  little  tubes  to  conduct  the 
water  from  the  lower  levels  of  soils  to  the  surface,  to 
supply  that  carried  away  by  evaporation.  The  coarser 
the  particles  of  soil  and  the  more  porous  it  is,  the 
larger  will  be  the  openings,  the  less  water  will  be  ab- 
sorbed from  the  rains,  and  the  more  rapid  the  escape 
from  the  surface  by  evaporation  into  the  atmosphere. 
In   soils   the   particles   of   which   are  not  too  finely   di- 


50  FIRST  PRINCIPLES  OF  AGRICULTURE. 

vided  and  too  compact,  the  reverse  is  the  case.  The 
tubes  and  pores  through  which  the  water  passes,  if  un- 
disturbed, admit  of  the  rapid  escape  of  water ;  if  dis- 
turbed, the  evaporation  is  arrested. 

Tillage  Conserves  Moisture.  —  Cultivating,  harrow- 
ing, and  rolling  disturb  or  break  the  connection  of  the 
pores  with  the  surface,  thus  reducing  the  evaporation 
until  the  connection  of  the  tubes  with  the  surface  is 
again  established.  The  amount  of  water  transpired  by 
growing  plants  is  enormous  —  from  three  to  five  hun- 
dred pounds  for  each  pound  of  dry  matter  formed ; 
and  its  escape,  other  than  through  the  plant,  should  be 
prevented  as  far  as  possible. 

Tillage  also  destroys  weeds,  which  require  for  their 
growth  quite  as  much  plant-food  and  moisture  as  culti- 
vated plants. 

For  cultivated  crops  frequent  tillage  is  recommended  in 
dry  seasons,  in  order  that  the  greatest  possible  amount 
of  moisture  may  be  retained  where  the  feeding  roots  are 
located ;  the  dry,  pulverized  surface  soil  acts  as  a  mulch 
or  blanket,  and  diverts  more  of  the  moisture  to  the 
roots  of  the  plant.  Too  deep  cultivation  in  dry  seasons 
frequently  does  more  harm  than  good,  unless,  in  the 
preparation  of  the  seed-bed,  the  soil  has  been  thor- 
oughly and  deeply  pulverized. 

Chemical  Improvement.  —  Soils  are  improved  chemi- 
cally by  the  addition  of  materials  which  contain  constit- 
uents that  are  liable  to  be  lacking,  or  which  have  the 
power  of  converting  dormant  into  active  constituents.  In 
many  cases  both  of  these  objects  are  accomplished  at 
the  same  time.     Materials  containing  nitrogen,  phosphoric 


J 

THE  IMPROVEMENT  OF  SOIL &*    HV        51 

acid,  and  potash  are  usually  regarded  as  belonging  to  the 
first  class ;  while  lime  itself,  and  materials  containing 
lime,  belong  more  particularly  to  the  second  class.  Lime 
is  one  of  the  most  useful  agents  of  the  farmer,  and  does 
not,  as  is  commonly  believed,  have  the  tendency  to  ex- 
haust soils  unduly,  when  its  use  is  properly  understood. 
Lime  acts  powerfully  upon  and  hastens  the  decay  of 
organic  matter  from  both  vegetable  and  animal  sources, 
by  virtue  of  which  the  nitrogen  becomes  more  quickly 
available  to  plants,  and,  as  already  stated,  lime  also  as- 
sists in  the  process  of  nitrification.  Lime  further  aids 
in  liberating  potash  from  insoluble  compounds  in  the  soil, 
thus  increasing  the  store  of  active  plant-food  ingredients ; 
it  also  promotes  the  formation  of  compounds  with  alu- 
mina, which  have  the  power  of  retaining  ammonia  and 
potash.  The  direct  effect  of  lime,  as  well  as  the  other 
materials  furnishing  plant-food,  will  be  discussed  in  de- 
tail in  the  chapter  on  manures. 


52  FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER  V. 
Natural  Manures. 

A  manure  is,  in  a  broad  sense,  anything  that  aids  or 
increases  the  production  of  farm  crops.  Manures  may 
be  direct  in  their  effect,  by  adding  to  the  actual  plant- 
food  in  the  soil,  or  indirect,  by  aiding  the  decay,  and 
making  active  insoluble  plant-food  constituents  in  the  soil. 

It  was  shown  in  previous  chapters,  that,  of  all  of  the 
constituents  which  plants  need,  but  four  were  liable  to 
be  exhausted  by  any  system  of  cropping;  these  were 
nitrogen,  phosphoric  acid,  potash,  and  lime.  Direct  ma- 
nures contain  one  or  two  or  all  of  these  constituents.  Any- 
thing called  a  "  direct  manure,"  which  does  not  contain 
one  or  more  of  these  constituents,  cannot  add  to  the  stock 
of  true  plant-food. 

Essential  Fertilizing  Elements. — Nitrogen,  phos- 
phoric acid,  potash,  and  lime  are  called  the  essential  fer- 
tilizing elements,  because  they  are  more  important  in 
manures  than  the  others  that  plants  require ;  and  a  direct 
manure  is  useful  in  proportion  to  the  amount  and  avail- 
ability, or  direct  usefulness,  of  these  constituents  con- 
tained in  it. 

Direct  manures  may  also  be  indirect  at  the  same  time ; 
that  is,  they  may  contain  materials  which  add  no  plant- 
food  directly,  but  which  act  upon  the  soil  constituents. 


NATURAL  MANURES.  53 

Indirect  manures  are  valuable  in  proportion  to  the 
effect  which  they  have  upon  the  soil  constituents,  and 
this  effect  may  be  due  to  both  physical  and  chemical 
causes.  Through  this  distinction,  in  reference  to  the 
action  of  manures,  we  are  ready  to  classify  them  into 
natural  manures  and  artificial  manures. 

Natural  Manures.  —  A  natural  manure  is  one  which 
may  be  either  direct  or  indirect,  but  which  has  been 
derived  from  natural  sources,  or,  in  other  words,  which 
has  not  undergone  any  specific  treatment  or  manufac- 
ture. These  include  all  vegetable  and  animal  refuse  of 
the  farm  and  yard,  also  factory  wastes,  which  contain 
one  or  more  of  the  essential  constituents.  Natural  ma- 
nures are  as  a  rule  bulky,  and  are  low  grade  in  the  sense 
that  they  contain  small  amounts  of  the  direct  plant-food 
constituents. 

Farmyard  manure  is  one  of  the  most  important  and 
useful  of  the  natural  manures ;  it  is  both  a  direct  and 
an  indirect  manure :  direct,  in  containing  nitrogen,  phos- 
phoric acid,  potash,  and  lime,  which  are  actual  fertiliz- 
ing constituents;  and  indirect,  in  containing  organic  or 
vegetable  matter,  which  aids  in  the  improvement  of  the 
physical  character  of  the  soil. 

It  is  sometimes  called  a  "general  manure,"  because, 
as  it  contains  all  of  the  constituents  of  plant  growth,  it 
is  liable  to  be  generally  useful  on  all  soils. 

Farmyard  Manure.  —  Yard  manure  varies  in  its 
composition  according  to  the  character  of  the  animals 
producing  it,  and  the  quality  of  the  food,  and  the  object 
of  feeding.  Its  composition  is  also  influenced  by  the 
amount  and  kind  of  litter  used,  and  its  management  after 


54  FIRST  PRINCIPLES  OF  AGRICULTURE. 

it  is  secured.  The  manure  from  young  animals  is  less 
valuable  than  that  made  when  the  animals  are  full 
grown. 

Manure  made  from  fattening  animals  is  richer  than 
that  produced  by  dairy  cows;  animals  fed  upon  hay  and 
straw  furnish  manure  much  less  valuable  than  when  the 
cereal  grains  constitute  a  part  of  the  ration. 

Manure  Produced  by  Different  Animals.  —  Horse 
manure  is  richer  in  nitrogen,  contains  less  water,  and  is 
less  variable  in  composition  than  that  obtained  from  cows. 
The  manure  made  from  animals  consuming  rich  food  is 
more  liable  to  fermentation  than  that  produced  when 
they  are  fed  upon  bulky  fodders  or  watery  feeds. 

Horse  manure  is  called  a  "  hot  manure "  because  of 
its  tendency  to  hot  fermentation;  and  is  for  this  reason 
particularly  useful  for  hot-beds,  and  for  forcing  early 
growth.  Cow  manure,  on  the  other  hand,  is  called  a 
"  cold  manure,"  because  less  liable  to  fermentation.  Sheep 
manure  contains  less  water,  and  is  richer  in  the  fertiliz- 
ing constituents  than  either  horse  or  cow  manure.  Pig 
manure,  while  quite  as  watery  as  cow  manure,  is  richer 
in  nitrogen. 

Composition  of  Stable  Manure.  —  Manure  from  horse 
stables  in  large  cities  also  varies  considerably  in  compo- 
sition. It  contains  on  the  average  seventy-five  per  cent, 
or  fifteen  hundred  pounds  per  ton,  of  water,  and  twenty- 
five  per  cent,  or  five  hundred  pounds  per  ton,  of  dry 
matter,  which  contains  all  of  the  manurial  ingredients. 
The  water  is  of  no  particular  value  ;  it  simply  increases 
the  cost  of  handling.  The  dry  matter  consists  of  from 
ten  to   twelve   per  cent  of  ash,  and  from  twelve  to  fif- 


NATURAL  MANURES.  55 

teen  per  cent  of  organic  matter.  The  ash  contains  from 
eight  to  ten  pounds  each  of  phosphoric  acid  and  lime, 
and  six  to  eight  pounds  of  potash ;  while  the  organic 
matter  contains  from  eight  to  ten  pounds  of  nitrogen. 

Its  indirect  value,  however,  is  often  quite  as  great  as, 
and  frequently  greater  than,  its  direct  value,  —  first,  be- 
cause of  its  vegetable  matter,  which  materially  improves 
the  absorbing  and  retaining  power  of  soils ;  and  second, 
because  of  the  lower  forms  of  life,  or  bacteria,  contained 
in  it,  which  induce  useful  fermentations  in  the  soil. 
Not  including  the  lime,  the  average  ton  of  city  manure 
contains  but  twenty-eight  pounds  of  actual  fertilizer  con- 
stituents. 

Solid  and  Liquid  Portions.  —  The  nitrogen  digested 
from  the  food,  as  well  as  a  large  part  of  the  potash,  is 
found  in  the  liquid  portions  of  the  manure ;  while  the 
nitrogen  in  the  undigested  portions,  as  well  as  a  large 
part  of  the  phosphoric  acid,  is  contained  in  the  solid 
residue.  The  nitrogen  in  the  urine  is  largely  in  the 
form  of  "urea,"  a  compound  soluble  in  water,  and  is 
easily  decomposed ;  the  potash  is  also  soluble  in  water. 
These  constituents  are,  therefore,  the  most  active. 

Sources  of  Loss  in  Manures.  —  Manures  are  sus- 
ceptible to  two  direct  sources  of  loss,  the  first  of  which 
is  due  to  fermentation,  which  results  in  the  loss  of  ni- 
trogen ;  and  the  second  is  due  to  leaching,  which  may 
finally  result  in  a  loss  of  all  the  constituents,  though  it 
is  confined  largely  to  the  soluble  nitrogen  and  potash. 
By  fermentation,  the  nitrogen  in  the  manure  is  changed 
to  ammonia,  usually  in  the  form  of  a  carbonate,  which 
is  volatile,  and  escapes  into  the  atmosphere. 


5Q  FIRST  PRINCIPLES  OF  AGRICULTURE. 

Care  of  Manures.  —  Fermentation,  causing  loss,  may 
be  prevented  by  keeping  the  manure  moist  and  well 
packed.  The  loss  through  leaching  may  be  stopped  if 
the  passage  of  water  through  it  is  prevented.  The  best 
^method  to  preserve  it  is  to  make  it  under  cover,  and  in 
pits  made  water-tight;  by  such  a  method  of  shelter  and 
protection  the  maximum  amount  of  manurial  value  is 
obtained.  The  soluble  constituents  are  prevented  from 
being  washed  into  the  drain,  and  the  loss  of  volatile 
compounds  is  reduced  to  a  minimum.  Where  it  is  not 
practicable  to  have  water-tight  pits,  it  should  be  kept  in 
yards  that  drain  to  the  centre,  plenty  of  absorbent  used, 
and  drainage  from  the  roof  not  allowed  to  run  in  the 
yard ;  and  the  product  should  be  removed  to  the  field  as 
often  as  possible. 

Experiments  conducted  to  determine  the  extent  of  the 
loss  of  valuable  constituents  due  to  improper  fermenta- 
tion and  to  leaching  have  shown,  that,  under  average 
conditions  of  season,  the  loss  from  exposure  for  six 
months  will  range  from  one-third  to  one-half  of  the  total 
constituents;  this  loss  falls  upon  the  most  active  forms, 
the  constituents  remaining  in  the  manure  after  being  sub- 
jected to  such  losses  are  the  least  active  and  directly 
useful. 

Manure  Preservers.  —  The  loss  of  ammonia,  both  in 
the  stables  and  in  manure  pits,  may  also  be  prevented  by 
the  use  of  land  plaster,  of  kainit,  or  of  superphosphate, 
which  has  the  power  of  fixing  and  retaining  the  vola- 
tile gases.  A  pound  a  day  per  grown  animal,  sprinkled 
around  in  the  stable,  is  sufficient  to  attain  the  object. 
The  same  proportion  and  amount  may  be  used  on  the 


NATURAL  MANURES.  57 

manure  heap.  The  value  of  this  practice  is,  however, 
measured  by  the  care  of  the  manure  afterward,  since  the 
fixed  constituents  are  still  liable  to  loss  from  leaching. 

The  Improvement  of  Manures.  —  Manures  are  im- 
proved as  they  are  reduced  in  bulk,  and  as  the  constit- 
uents are  made  available  or  directly  useful ;  this  is 
accomplished  by  well-regulated  fermentation,  or  rotting. 
By  well-regulated  fermentation  is  meant  that  which  re- 
sults in  the  decay  of  organic  matter  with  the  least  loss 
of  nitrogen.  The  loss  from  fermentation  is  greatest 
when  the  manure  lies  in  loose  heaps,  the  access  of  air 
aiding  the  decay;  the  loss  is  least  when  it  is  packed 
and  moist.  The  mixing  of  the  manures  of  the  various 
farm  animals,  hot  and  cold,  also  tends  to  reduce  fermen- 
tation. 

If  the  fermentation  becomes  too  active,  great  heat  is 
developed,  which  causes  the  rapid  escape  of  moisture;  the 
manure  is  burned  and  has  a  whitish  and  mouldy  appear- 
ance,—  it  is  what  is  called  "  fire-fanged."  Under  these 
circumstances  there  is  frequently  a  loss  of  nitrogen.  The 
"  fire-fanging "  may  be  prevented  by  keeping  the  heap 
moist. 

It  is  evident,  therefore,  that  the  improvement  of 
manures,  while  it  reduces  bulk  and  increases  availability 
of  the  fertilizing  elements,  requires  care  and  labor. 
Whether  such  improvement  will  pay  or  not  depends, 
first,  upon  the  cost  of  labor,  and  second,  upon  the  object 
of  use  of  the  manure.  Where  labor  is  expensive,  and 
the  manure  is  used  for  the  growing  of  such  gross-feed- 
ing field  crops  as  corn,  the  advantages  derived  are  least. 
When  the   handling    can   be  performed    by   the   regular 


58  FIRST  PRINCIPLES   OF  AGRICULTURE. 

labor  of  the  farm,  and  where  the  manure  is  applied  to 
garden  or  quick-growing  crops,  the  advantages  of  such 
improvement  are  greatest. 

On  the  whole,  however,  it  is  safe  to  estimate  that  the 
least  labor  necessary  to  get  the  manure  from  the  animal 
to  the  field  is  the  best  policy ;  that  is,  while  there  may 
be  loss,  and  while  the  constituents  may  not  be  so  active, 
still,  the  financial  results  attained  are,  because  of  the 
saving  of  labor,  quite  as  good. 

There  is  another  advantage  in  the  careful  fermentation 
of  manures  which  should  not  be  overlooked,  particularly 
on  soils  poor  in  vegetable  matter ;  that  is,  the  development 
of  useful  bacteria,  the  work  of  which  has  been  already 
described.  What  has  been  said  in  reference  to  yard 
manure  is  also  true  for  other  manures  of  the  farm. 

Poultry  Manure.  —  This  is  richer  in  all  of  the  essen- 
tial elements  than  any  other  natural  manure  of  the 
farm.  It  contains  less  water,  and  is  not  so  liable  to  hot 
fermentation  if  kept  moist. 

Application  of  Yard  Manure.  —  Two  points  should 
be  kept  in  mind  in  the  application  of  yard  manures, — 
first,  that  they  are  essentially  nitrogenous  products ;  and 
second,  that  they  are  particularly  valuable  because  of 
the  useful  ferments  contained  in  them.  If  too  much  is 
added  at  one  time,  a  loss  of  nitrogen  is  liable  to  follow, 
and  the  benefits  derived  from  the  ferments  are  limited 
to  small  areas.  The  manure  of  the  farm  should  be 
distributed  as  far  as  possible,  and  supplemented  by 
more  concentrated  materials.  Coarse  manures  are  better 
adapted  for  heavy  lands,  while  those  which  are  well 
rotted  are  more  useful  on  light  soils. 


NATURAL  MANURES.  59 

Composts.  —  In  addition  to  the  yard  manure,  there 
are  about  most  farms  wastes  of  considerable  importance, 
weeds,  grasses,  and  coarse  growths  of  any  kind,  which 
all  contain  greater  or  less  amounts  of  the  manurial  con- 
stituents. These  should  be  carefully  utilized,  and  may 
be  profitably  used  as  absorbents  in  the  barnyard.  When 
this  method  is  adopted,  the  weeds  should  be  cut  before 
they  have  matured,  or  they  furnish  an  excellent  means 
of  transmitting  foul  seeds.  These  waste  products  may 
also  be  used  in  making  what  are  called  "composts." 
These,  of  course,  differ  according  to  the  conditions  of 
the  farmer.  Where  peat  or  muck  is  available,  they 
are  more  advantageous  than  where  such  products  are 
not  at  hand.  The  main  object  of  the  compost  heap  is 
to  cause  a  more  rapid  decay  of  such  products,  and  without 
the  loss  of  essential  constituents. 

A  good  compost  heap  may  be  made  by  placing  a  layer 
of  manure,  then  a  layer  of  the  weeds  or  waste  products 
of  any  kind,  then  a  layer  of  lime  or  ashes,  the  whole 
well  moistened,  and  the  order  repeated  until  all  of  the 
products  are  used.  The  manure  starts  fermentation,  the 
lime  aids  in  the  rotting,  as  well  as  to  prevent  acidity 
and  to  keep  the  heap  alkaline,  and  the  moisture  pre- 
vents too  hot  fermentation.  By  careful  management 
destructive  fermentation  is  prevented,  the  bulk  is  very 
materially  reduced,  and  the  quality  of  the  constituents 
greatly  improved.  The  chief  difficulty  in  the  making 
of  composts,  as  well  as  with  other  methods  used  in  the 
improvement  of  manures,  is  the  expense  of  labor. 

It  pays  to  take  good  care  of,  and  to  save,  manurial 
products,  and  to  see  to  it  that  wastes  are   reduced,  and 


60  FIRST  PRINCIPLES  OF  AGRICULTURE. 

the  improvement  of  the  quality  of  the  constituents  by  the 
methods  suggested  is  frequently  of  considerable  financial 
advantage. 

Muck,  or  Peat.  —  On  many  farms  there  are  low,  wet 
places  where  the  conditions  are  favorable  for  the  collec- 
tion of  partially  decayed  vegetable  matter.  The  mate- 
rial thus  formed  is  called  "muck,"  or  "peat."  The 
thickness  of  the  deposit  and  its  character  depend  upon 
the  time  during  which  it  has  been  formed,  and  the 
character  of  the  climate. 

Muck  is  used  mainly  as  a  source  of  humus,  and  as 
an  absorbent  for  use  in  stables  or  yards.  Fresh  muck 
contains  on  the  average  seventy-five  per  cent  of  water, 
three-tenths  per  cent  of  nitrogen,  and  traces  of  potash, 
phosphoric  acid,  and  lime.  Air-dry  muck  contains  on 
the  average  twenty-one  per  cent  of  water,  one  and  one- 
third  per  cent  of  nitrogen,  one-tenth  per  cent  each  of 
phosphoric  acid  and  potash,  and  nine-tenths  per  cent  of 
lime.  The  value  of  the  muck  as  a  source  of  humus  is 
measured  by  its  content  of  nitrogen,  while  its  value  as 
an  absorbent  depends  upon  its  content  of  organic  matter. 
The  usefulness  of  muck  for  either  of  these  purposes  is 
further  modified  by  the  labor  necessary  to  secure  it  in  a 
dried  condition. 

The  usual  method  of  procuring  it  is  to  throw  it  out 
of  the  bed  into  heaps,  and  allow  it  to  dry  before  it  is 
used  either  upon  the  fields  or  in  the  stables.  Where  a 
muck  bed  exists  upon  a  farm,  it  should  first  be  studied 
in  reference  to  its  possible  drainage.  If  it  can  be  drained, 
it  is  liable  to  prove  more  useful  where  it  lies  than  for 
the  other  purposes  mentioned;  since  soils  rich  in  peaty 


NATURAL  MANURES.  61 

matter  are  particularly  valuable,  when  properly  managed, 
for  growing  onions,  celery,  and  potatoes.  Large  areas  of 
peaty  soils  in  this  country,  that  have  been  properly 
drained,  are  now  devoted  to  these  crops ;  before  draining 
they  were  absolutely  valueless. 

In  addition  to  the  natural  farm  wastes,  farmers  fre- 
quently have  easy  access  to  certain  factory  wastes.  These 
may  be  divided  into  two  classes,  nitrogenous  and  potassic. 
Of  the  nitrogenous  materials,  wool  and  hair  wastes  are 
probably  the  most  important.  These  are  very  rich  in 
nitrogen;  both  are,  however,  usually  mixed  with  other 
materials,  and  vary  widely  in  their  composition. 

Wool  Waste.  —  Wool  waste  contains  on  an  average 
ten  per  cent  of  water,  five  and  one-half  per  cent  of  nitro- 
gen, one  per  cent  of  phosphoric  acid,  and  two  per  cent 
of  potash. 

Hair  Waste.  —  An  average  analysis  of  hair  waste,  as 
determined  at  the  New  Jersey  Experiment  Station,  shows 
it  to  contain  thirty-two  per  cent  of  water,  seven  and  two- 
tenths  per  cent  of  nitrogen,  and  eight-tenths  per  cent  of 
phosphoric  acid. 

Felt  Waste.  —  Felt  waste  is  similar  to  wool  waste 
in  that  its  nitrogen  is  contained  in  the  wool,  though 
variable  in  composition  on  account  of  the  varying  pro- 
portions of  cotton  used  in  its  manufacture.  Analyses 
show  it  to  contain  about  eight  per  cent  of  nitrogen. 

Leather  Meal.  —  Leather  meal  is  a  product  found  in 
considerable  quantities  in  towns  where  the  manufacture 
of  shoes  is  an  industry.  It  contains  on  the  average  ten 
per  cent  of  water,  and  seven  of  nitrogen.  The  nitrogen 
in.  the   leather  meal   is   even  less  available  than  in  the 


62  FIRST  PRINCIPLES  OF  AGRICULTURE. 

other  products  mentioned,  because  the  leather  has  passed 
through  a  process,  the  very  purpose  of  which  was  to  make 
it  less  liable  to  decay. 

The  purchase  of  these  materials  is  only  advisable  when 
they  can  be  procured  very  cheaply.  Their  application  is 
useful  when  the  object  is  gradual  increase  in  fertility, 
rather  than  immediate  increase  in  crop.  Hair  wastes 
have  been  found  advantageous  in  the  growing  of  ber- 
ries, hops,  and  other  slow-growing  crops,  while  wool  and 
leather  have  materially  improved  meadows  and  perma- 
nent pastures.  The  nitrogen  in  these  materials  is  im- 
proved in  form,  and  made  more  quickly  available,  when 
composted  with  manure. 

Wood- Ashes.  —  Of  the  potassic  manures,  unleached 
wood-ashes  are  the  most  useful.  The  pure  ashes  from 
the  different  varieties  of  wood  vary  in  composition ;  as 
a  rule,  the  softer  woods  contain  less,  and  the  hard  woods 
more,  potash,  the  range  being  from  sixteen  to  forty  per 
cent. 

Ashes  also  contain  lime  in  large  amounts,  while  phos- 
phoric acid  is  contained  in  much  smaller  quantities. 
Wood-ashes,  as  usually  gathered  for  market,  however,  con- 
tain very  considerable  portions  of  moisture,  dirt,  etc., 
which  cause  a  variability  in  composition  not  due  to  the 
character  of  the  woods  from  which  they  are  derived. 
The  average  analysis  of  commercial  wood-ashes  shows 
them  to  contain  less  than  six  per  cent  of  potash,  two 
per  cent  of  phosphoric  acid,  and  thirty-two  per  cent  of 
lime.  Leached  wood-ashes  contain  on  the  average  thirty 
per  cent  of  moisture,  one  and  one-tenth  per  cent  of  pot- 
ash, one  and  one-half  per  cent  of  phosphoric  acid,  and 
twenty-nine  per  cent  of  lime. 


NATURAL  MANURES.  63 

Ashes  are  probably  one  of  the  best  sources  of  potash 
that  we  have,  so  far  as  its  form  and  combination  are 
concerned,  being  in  a  very  fine  state  of  division,  and  in 
such  a  form  as  to  be  immediately  available  to  plants. 
Ashes  also  have  a  very  favorable  physical  effect  upon 
soils,  the  lime  present,  of  course,  aiding  in  this  respect. 
Canada  is  now  the  main  source  of  wood-ashes,  the  sub- 
stitution of  coal  for  wood  making  the  supply  in  this 
country  for  commercial  purposes  very  limited.  Owing 
to  the  variability  of  this  product,  it  should  always  be 
bought  subject  to  analysis,  and  to  a  definite  price  per 
pound  for  the  actual  constituents  contained  in  it ;  which 
should  not  be  greater  than  the  price  at  which  the  same 
constituents  could  be  purchased  in  other  quickly  available 
forms. 

Marl.  —  Marl  may  contain  one  or  more  of  the  constit- 
uents, phosphoric  acid,  potash,  and  lime.  Shell  marls 
are  usually  very  rich  in  lime,  but  contain  only  traces  of 
phosphoric  acid  and  potash.  The  green  sand  marls  of 
New  Jersey  often  contain  very  considerable  amounts 
of  phosphoric  acid  and  potash,  though  they  vary  widely 
in  composition.  They  contain  on  the  average  two  and 
two-tenths  per  cent  of  phosphoric  acid,  four  and  seven- 
tenths  per  cent  of  potash,  and  two  and  nine-tenths  per 
cent  of  lime.  These  constituents,  particularly  the  potash, 
are,  as  a  rule,  slowly  available. 

Marl,  however,  is  an  important  amendment  to  soils, 
not  only  because  of  its  content  of  mineral  constituents, 
but  because  these  constituents  are  associated  with  pro- 
ducts that  have  a  very  favorable  mechanical  effect  upon 
soils.      Large  areas  of  land  in  the  State  of  New  Jersey 


64  FIRST  PRINCIPLES   OF  AORICULTURE. 

formerly  unproductive,  chiefly  because  of  physical  imper- 
fections, have  been  made  very  productive  mainly  through 
the  application  of  marl. 

The  use  of  marl  is  now  less  general  than  when  the 
fertilizing  constituents  from  artificial  sources  were  dearer, 
and  when  the  labor  of  the  farm  was  more  abundant  and 
cheaper.  The  quicker  effect  of  more  soluble  fertilizer 
constituents  has  had  an  influence  in  reducing  the  use  of 
marl  where  quick  returns  are  desirable.  Where  farmers 
have  deposits  upon  their  own  farms,  or  within  short  dis- 
tances of  them,  and  can  secure  it  at  a  low  price  per  ton, 
it  is  a  desirable  method  of  improving  land. 

The  results  from  the  use  of  marl  are  frequently  due 
quite  as  much  to  the  improvement  given  to  the  physical 
condition  of  soils  as  to  the  increase  in  fertility  furnished 
by  the  essential  mineral  constituents.  Marls  may  be 
carted  and  spread  upon  the  land  when  other  work  of 
the  farm  is  not  pressing,  thus  making  it  possible  to  get 
a  considerable  addition  of  fertility  at  a  small  expense. 

Lime.  —  Lime,  while  an  essential  constituent  of  plants, 
is  usually  more  abundant  in  soils  than  the  other  mineral 
constituents,  phosphoric  acid  and  potash.  It  is,  how- 
ever, regarded  as  a  direct  source  of  plant-food  in  a  great 
many  cases,  though  its  greatest  value  lies  in  its  favorable 
action  upon  soils.  This  action  is  both  physical  and 
chemical,  and  has  already  been  discussed  in  a  previous 
chapter. 

Lime,  as  is  it  generally  understood,  is  an  oxide  of  cal- 
cium, and  is  produced  by  burning  limestone,  or  carbonate 
of  lime.  The  lime  loses  the  carbonic  acid  when  burned  in 
the  kilns,  and  the  oxide  of  lime  remains  behind ;  this  is 


NATURAL  MANURES.  65 

usually  termed  u  quicklime."  The  quicklime,  before  it  is 
applied  to  the  soil,  is  usually  slaked;  this  is  done  by 
adding  water,  which  the  lime  absorbs,  and  falls  to  a  pow- 
der. Slaked  lime,  also  called  caustic  lime,  is  a  calcium 
hydrate. 

The  more  completely  limestone  is  burned,  the  better 
the  quicklime,  and  the  more  completely  it  slakes.  We 
have,  when  we  speak  of  lime,  three  forms :  limestone, 
quicklime,  or  burned  lime,  and  slaked  lime,  each  differing 
from  the  other  in  composition. 

Quicklime  absorbs  moisture,  and  slakes  when  exposed 
to  the  atmosphere.  Lime  thus  slaked  is  called  "  air- 
slaked  lime,"  and  is  usually  less  completely  changed  to 
a  hydrate  than  when  water  is  added.  Quicklime  also 
absorbs  carbonic  acid  from  the  air,  and  changes  back  to 
the  limestone  form.  Lime  in  the  carbonated  form,  if 
finely  pulverized,  is  better  for  liming  light  lands  than 
the  caustic  lime ;  for  heavy  lands,  caustic  is  preferable 
to  the  carbonate. 

What  is  termed  "  marble  lime "  is  made  from  pure 
limestone.  What  are  called  "  limestones "  frequently 
contain  considerable  magnesia,  in  which  case  they  are 
termed  "  magnesian  limestones."  The  larger  number  of 
the  limestones  of  New  Jersey  are  of  this  class ;  they 
contain  from  fifty  to  sixty  per  cent  of  calcium  oxide, 
and  thirty  per  cent  or  over  of   oxide  of   magnesia. 

Oyster  shells  are  nearly  pure  carbonate  of  lime ;  oyster- 
shell  lime,  though  containing  no  magnesia,  is  usually 
mixed  with  more  or  less  dirt  and  other  impurities,  and 
is  therefore  not  as  rich  in  lime  as  that  derived  from 
pure  limestone. 


66  FIRST  PRINCIPLES  OF  AGRICULTURE. 

Gas-Lime.  —  The  lime  from  gas-works  is  also  fre- 
quently used  as  manure ;  in  these  works  quicklime  is 
used  for  removing  the  impurities  from  the  gas.  Gas- 
lime,  therefore,  varies  considerably  in  composition,  and 
consists  really  of  a  mixture  of  slaked  lime,  or  calcium 
hydrate,  and  carbonate  of  lime,  together  with  sulphides 
and  sulphites  of  lime.  These  last  are  injurious  to  plant 
life,  and  gas-lime  should  be  applied  long  before  the  crop 
is  planted,  or  at  least  exposed  to  the  air  some  time 
before  its  application  ;  the  action  of  air  converts  the 
poisonous  substances  in  it  into  non-injurious  products. 
Gas-lime  contains  on  an  average  forty  per  cent  of  cal- 
cium oxide. 

Gypsum  or  Land  Plaster.  —  Gypsum  is  a  sulphate 
of  lime  containing  water  in  combination.  Pure  gypsum 
contains  thirty-two  and  one-half  per  cent  of  lime,  forty- 
six  and  one-half  per  cent  of  sulphuric  acid,  and  twenty- 
one  per  cent  of  water. 

Plaster  of  Paris  is  prepared  from  pure  gypsum  by 
burning,  which  drives  off  the  water  it  contains.  Gyp- 
sum, like  other  forms  of  lime,  furnishes  directly  the 
element  calcium,  and  also  exerts  a  favorable  solvent 
effect  upon  the  soil.  It  was  formerly  used  in  large  quan- 
tities, particularly  for  clover;  and  it  is  believed  that  its 
favorable  effect  was  due,  not  so  much  to  the  direct  addi- 
tion of  lime,  as  to  its  action  upon  insoluble  potash  com- 
pounds in  the  soil,  in  setting  free  potash.  Thus  the 
application  of  plaster  caused  an  increase  in  crop  because 
of  the  potash  made  available. 

We  have  in  the  Eastern  States  two  main  sources  of 
gypsum,  namely,  Nova  Scotia  and  Cayuga,  N.Y.      Nova 


NATURAL  MANURES.  67 

Scotia  plaster  is  purer  than  that  obtained  from  New 
York.  The  New  York  plaster,  however,  frequently  con- 
tains appreciable  amounts  of  phosphoric  acid. 

Salt.  —  Common  salt  is  sometimes  used  as  a  manure. 
It  supplies  no  essential  plant-food  constituents;  and  its 
value  is  still  a  disputed  point,  though  it  is  admitted 
that,  where  its  use  is  favorable,  it  is  due  to  indirect 
action  in  aiding  the  decomposition  of  animal  and  vege- 
table matter,  increasing  the  absorbing  power  of  soils,  and, 
by  its  reaction  with  lime,  acting  as  a  solvent  for  phos- 
phates. Salt  is  frequently  applied  in  connection  with 
nitrate  of  soda  for  wheat  crops,  to  prevent  a  too  rapid 
growth  of  straw. 

The  Application  of  Lime The  quantity  of  lime  to 

be  applied  may  vary  according  to  circumstances ;  heavy 
lands,  rich  in  organic  matter,  may  receive  more,  and 
lighter  lands,  less.  The  usual  amount  in  the  Eastern 
States,  on  average  land,  ranges  from  one  to  three  tons 
of  quicklime  per  acre.  This  is  applied  once  in  six  or 
seven  years,  the  application  of  small  quantities  being 
frequently  more  useful  than  large  quantites  applied  at 
wider  intervals.  Lime  should  be  applied  on  the  surface, 
as  its  tendency  is  to  work  into  the  soil,  and  gradually 
get  below  the  surface  soil.  The  time  of  application, 
also,  varies  with  the  kind  of  crop  and  the  character 
of  the  soil.  For  pasture-lands  or  mowing-fields,  the 
early  spring  or  fall  are  the  best  seasons  to  apply  it. 
It  should  never  be  used  directly  with  commercial  fertil- 
izers containing  ammonia  and  soluble  phosphoric  acid, 
as  it  sets  free  the  ammonia,  and  reduces  the  solubility 
of  the  phosphates. 


68  FIRST  PRINCIPLES   OF  AGRICULTURE. 


CHAPTEE   VI. 
Artificial  and  Concentrated  Manures;  Nitrogenous  Materials. 

As  farm  lands  become  exhausted  of  their  essential 
plant-food  constituents  by  the  continual  sale  of  crops, 
the  manures  available  to  the  farmer,  both  from  the 
natural  wastes  of  the  farm  and  from  such  materials  as 
lime,  ashes,  etc.,  are  often  insufficient  to  keep  up  their 
original  fertility.  At  the  present  time,  too,  the  tendency 
of  farming  in  this  country,  especially  in  the  Eastern 
States,  and  in  the  vicinity  of  large  cities,  is  toward 
special  crop  farming,  which  requires  that  soils  should 
be  abundantly  supplied  with  active  plant-food. 

These  conditions  have  caused  a  rapid  development  of 
the  sources  of  supply  of  suitable  materials  that  furnish 
the  constituents  liable  to  be  lacking,  or  contained  in  too 
small  amounts,  in  the  soil ;  viz.,  nitrogen,  phosphoric  acid, 
and  potash. 

Classes  of  Materials.  —  These  materials  are  divided 
into  three  distinct  classes,  —  namely,  nitrogenous,  furnish- 
ing nitrogen ;  phosphatic,  furnishing  phosphoric  acid  j  and 
potassic,  furnishing  potash. 

Manures  made  from  these  materials  are  called  "arti- 
ficial," "  concentrated,"  or  "  commercial."  They  differ 
from  the  natural  manures  mainly  in  being  more  con- 
centrated,   though    frequently   the  constituents    in  them 


ARTIFICIAL  AND   CONCENTRATED  MANURES.     69 

are  more  immediately  available  to  the  plant.  The  manu- 
rial  elements,  if  in  a  form  in  which  plants  can  use 
them,  are  quite  as  much  actual  plant-food  when  contained 
in  these  materials  as  when  furnished  by  the  more  familiar 
natural  manures. 

Natural  manurial  products,  or  homemade  materials, 
are  used  in  their  original  state  or  applied  directly  to  the 
soil.  Artificial  products,  as  a  rule,  require  treatment 
previous  to  their  use. 

Nitrogen.  —  Nitrogen  is  the  most  costly  element  of 
manures.  It  is  absolutely  essential  to  all  organized  life, 
whether  animal  or  vegetable;  it  is  the  basis  of  the  al- 
buminoids of  plants,  the  casein  of  milk,  and  the  fibrin 
of  blood.  Nitrogen  occurs  in  three  forms,  and  all  these 
forms  exist  as  commercial  manure  products.  The  form 
means  its  combination  with  other  chemical  elements; 
namely,  nitrogen  as  nitrates,  nitrogen  as  ammonia,  and 
nitrogen  as  organic  matter. 

Forms  of  Nitrogen.  —  Nitrogen  in  the  form  of  a 
nitrate  means  its  combination  with  oxygen  in  such  pro- 
portions as  to  form  nitric  acid,  united  with  a  base  like 
soda  or  potash;  thus,  we  have  nitrates  of  soda,  potash, 
lime,  etc. 

Nitrogen  as  ammonia  means  its  combination  with 
hydrogen  in  such  proportion  as  to  form  ammonia.  Am- 
monia gas  consists  of  one  part  of  nitrogen  and  three 
of  hydrogen.  This  gas  readily  combines  with  various 
acids,  as  sulphuric,  nitric,  etc.,  to  form  ammonia  salts. 

Nitrogen  in  the  form  of  organic  matter  means  its  com- 
bination with  the  chemical  constituents,  carbon,  hydrogen, 
and   oxygen,   either    as   animal   or  vegetable   substances. 


70  FIRST  PRINCIPLES   OF  AGRICULTURE. 

A  large  number  of  materials,  differing  widely  in  their 
character  and  composition,  contain  nitrogen  in  this  form. 

Plants  that  derive  their  nitrogen  from  the  soil  absorb 
it  chiefly  in  the  form  of  a  nitrate;  when  nitrogen  is 
applied  in  this  form,  no  changes  are  required  to  enable 
it  to  serve  as  a  direct  food.  Materials  furnishing  nitrates 
are,  therefore,  regarded  as  of  the  greatest  importance  in 
the  manufacture  of  commercial  manures. 

Ammonia,  while  it  does  nourish  plants  directly,  usually 
undergoes  a  change  into  nitrate  first,  though  this  change 
proceeds  rapidly  when  the  conditions  mentioned  as  favor- 
able for  nitrification  are  present.  As  a  rule,  therefore, 
an  appreciable  time  does  elapse  before  all  the  nitrogen 
in  ammonia  serves  as  plant-food. 

Nitrogen  in  organic  forms  is  first  changed  by  the 
decay  or  rotting  of  the  substance  into  ammonia,  and  the 
ammonia  is  then  changed  into  a  nitrate.  The  rapidity 
of  this  decay  depends  both  upon  the  character  of  the 
substance  itself,  and  upon  its  physical  form  and  its 
mechanical  conditions  or  fineness  of  division.  The 
tougher  and  more  dense  the  substance,  and  the  coarser 
the  particles,  the  longer  the  time  required  to  rot,  and 
the  more  slowly  available  as  nitrogenous  food.  The  rapid- 
ity with  which  nitrogen  may  become  useful  as  food  to 
plants  is,  therefore,  determined  by  its  chemical  form. 

Nitrates,  since  they  are  immediately  useful  to  the 
plant,  may  all  be  absorbed  by  the  crop  upon  which  they 
are  applied,  while  ammonia  salts  and  organic  nitrogen 
may  be  only  partially  used,  because  the  necessary  changes 
for  them  to  undergo  may  not  take  place  completely 
before  the  plant  is  fully  matured. 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     71 

The  different  results  obtained  from  the  use  of  the 
different  forms  of  nitrogen  determine  what  is  called  its 
"agricultural  value,"  or  the  improvement  it  causes  in 
the  growth  of  the  plant. 

This  agricultural  value,  which  is  true  of  any  manure, 
is,  too,  separate  and  distinct  from  the  commercial  value, 
or  cost  in  market ;  which  is  determined  by  market  and 
trade  conditions,  as  cost  of  production,  transportation, 
selling,  and  the  demand  for  it  in  other  industries.  It 
is  for  this  reason  that  the  best  forms  of  plant-food  may, 
and  frequently  do,  cost  less  per  pound  of  the  actual 
ingredient  than  when  furnished  by  other  more  slowly 
available,  and  less  directly  useful,  forms. 

Nitrate  of  Soda.  —  Nitrate  of  soda,  also  called  Chile 
saltpetre,  is  the  chief  source  from  which  nitrogen  as  a 
nitrate  is  secured  for  manurial  purposes.  It  possesses 
chemical  and  physical  properties  which  distinguish  it 
from  all  other  materials ;  it  is  a  salt  with  a  definite 
chemical  composition.  When  pure  it  contains  sixteen 
and  forty-seven  hundredths  per  cent  of  nitrogen. 

Vast  natural  deposits  of  the  crude  nitrate  salts  occur 
in  the  rainless  districts  of  South  America,  though  mainly 
in  Chile.  The  crude  salts  are  relatively  poor,  and  also 
variable  in  their  content  of  nitrogen ;  hence  before  ship- 
ment they  are  purified  by  dissolving  in  water  and  recrys- 
tallizing,  the  impurities  remaining  being  chiefly  water 
and  ordinary  salt. 

The  commercial  product  is  quite  pure,  containing  on 
the  average  sixteen  per  cent  of  nitrogen.  It  resembles 
in  appearance  ordinary  salt,  though  the  use  of  salt  as 
an   adulterant  has  not  been   practised   to  any  extent   in 


72  FIRST  PRINCIPLES   OF  AGRICULTURE. 

this  country.  It  is  completely  soluble  in  water,  diffuses 
readily  throughout  the  soil,  and,  since  it  forms  no  in- 
soluble compound  with  soil  constituents,  is  liable  to  be 
washed  into  the  lower  layers  of  the  soil,  and  finally  into 
the  drains,  if  applied  in  the  fall  of  the  year,  or  in  too 
large  quantities.  It  is  very  beneficial  for  early  and 
quick-growing  crops,  particularly  upon  light  sandy  soils, 
because  it  is  ready  for  use  as  soon  as  applied. 

The  soda  with  which  the  nitrate  is  combined  does  not 
possess  any  value  as  a  plant-food  constituent,  though 
it  is  believed  to  exert  a  beneficial  effect  upon  the  phys- 
ical character  of  soils.  This  value  is  not  taken  into 
account  in  commercial  transactions. 

The  use  of  nitrate  is  rapidly  increasing  where  its  ad- 
vantages are  well  known. 

Nitrate  of  potash,  or  saltpetre,  is  another  nitrate  salt 
used  to  some  extent,  though  its  cost  of  production  is 
too  great  to  admit  of  its  competition  with  the  nitrate 
of  soda.  It  is  a  concentrated  product,  and  furnishes 
potash  in  addition  to  the  nitrogen. 

Sulphate  of  Ammonia.  —  Ammonia  for  fertilizing 
purposes  is  secured  almost  entirely  from  sulphate  of  am- 
monia, which  is  another  chemical  salt  of  definite  com- 
position, and  is  one  of  the  most  concentrated  forms  in 
which  nitrogen  occurs.  It  contains,  when  pure,  twenty- 
one  and  two-tenths  per  cent  of  nitrogen.  It  is  derived 
chiefly  as  a  by-product  from  the  manufacture  of  gas  by 
the  dry  distillation  of  coal,  and  is  also  secured  in  smaller 
quantities  in  the  manufacture  of  bone-black  for  sugar  re- 
fineries, and  in  the  distillation  of  refuse  animal  matter. 

The   nitrogen   contained  in  these   products   is,  by  the 


ARTIFICIAL  AND   CONCENTRATED  MANURES.     73 

process  of  distillation,  viz.,  in  the  absence  of  air,  driven 
off  in  the  form  of  ammonia  gas,  which  is  conducted 
into  receptacles  containing  sulphuric  acid,  which  fixes 
the  ammonia  in  the  form  of  a  sulphate.  This  is  a 
crude  product,  and  is  usually  dissolved,  recrystallized, 
and  purified,  and  is  then  reasonably  uniform  in  compo- 
sition, and  contains  on  the  average  twenty  and  one-half 
per  cent  of  nitrogen.  When  sold  without  this  method  of 
purification,  it  is  called  "brown  sulphate  of  ammonia;" 
this  is  more  variable  in  composition,  with  moisture,  and 
insoluble  and  oily  matters  as  impurities.  Brown  sulphate 
often  contains  less  than  eighteen  per  cent  of  nitrogen. 
Sulphate  of  ammonia,  while  freely  soluble  in  water,  is 
readily  absorbed  by  the  soil,  and  may  be  applied  in  the 
fall  without  danger  of  serious  loss,  and  is,  next  to  ni- 
trate of  soda,  one  of  the  best  forms  of  nitrogen  for 
fertilizing  purposes.  It  is  a  particularly  useful  form  on 
clay  and  clay  loam  soils. 

Nitrates  and  ammonia  salts  possess  two  chief  advan- 
tages ;  viz.,  solubility,  hence  ease  of  distribution  in  the 
soil,  and  availability,  or  quick  usefulness  to  the  plant. 

The  cost  per  pound  of  nitrogen  in  the  form  of  am- 
monia is  usually  greater  than  for  the  nitrate  of  soda, 
because  of  the  comparatively  limited  supply,  and  be- 
cause more  largely  used  in  the  arts. 

Organic  Nitrogen.  —  Organic  nitrogen  is  obtained 
from  a  wide  variety  of  sources,  and  is  composed  of  both 
animal  and  vegetable  matter.  The  commercial  materi- 
als, from  whatever  source  derived,  unlike  the  salts  men- 
tioned, are  not  definite  chemical  compounds ;  those  of 
the   same    name,   even,   vary    in   their  composition,   and 


74  FIRST  PRINCIPLES   OF  AGRICULTURE. 

also  in  their  agricultural  value  or  usefulness  to  plants, 
largely  according  to  their  method  of  preparation  for 
market. 

Dried  blood,  for  instance,  is  rich  in  nitrogen  when 
carefully  prepared,  though  commercial  samples  show 
wide  variations  in  composition,  and  in  the  quality  of 
the  nitrogen.  A  pound  of  nitrogen,  therefore,  may  have 
a  very  different  value  in  one  sample  than  in  another, 
under  uniform  conditions  of  use,  while  under  the  same 
conditions  of  use  a  pound  of  nitrogen  in  the  form  of 
nitrate  is  equally  valuable  from  whatever  source  de- 
rived. 

Materials  containing  organic  nitrogen  are  not  soluble 
in  water,  and  the  nitrogen  is  not  immediately  available 
to  plants.  Their  value  as  a  source  of  this  element  is, 
therefore,  measured  by  conditions  which  favor  the  rapid 
change  of  their  nitrogen  into  soluble  and  available  forms. 
The  first  condition  is  fineness  of  division,  which  permits 
of  a  more  even  distribution,  and  the  exposing  of  a 
larger  surface  area  to  the  action  of  the  agencies  in  the 
soil  and  air;  and  the  second  is  the  physical  character 
of  the  material  itself.  If  it  is  hard  and  dense,  decay 
will  be  slower,  since  the  processes  which  cause  it  are 
resisted;  if  soft  and  porous,  the  rotting  is  more  rapid, 
because  the  agencies  which  cause  it  are  encouraged  to 
act. 

Dried  Blood.  —  Dried  blood  is  one  of  the  most  valua- 
ble sources  of  organic  nitrogen.  Its  fineness  of  division 
permits  of  its  easy  and  uniform  distribution,  and  its 
physical  character  is  such  as  to  encourage  rapid  decay 
under  suitable  conditions. 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     75 

What  is  called  "  high-grade  blood  "  is  red  in  color,  and 
is  quite  uniform  in  composition,  ranging  from  twelve  to 
fourteen  per  cent  of  nitrogen.  This  form  of  blood  is 
used  largely  in  the  arts,  hence  the  supply  for  manurial 
purposes  is  limited :  lower  grades  are  in  greater  supply ; 
these  are  darker  in  color,  vary  widely  in  composition 
and  physical  character,  and  frequently  contain,  as  im- 
purities, moisture,  hair,  bone,  etc. ;  the  two  latter,  to  be 
sure,  contain  nitrogen,  but  in  forms  less  useful  than  in 
the  blood. 

Dried  Meat,  or  Azotine.  —  This  material  is  proba- 
bly, next  to  blood,  the  most  important  source  of  organic 
nitrogen.  It  is  obtained  by  separating  the  meat  from 
the  bones,  extracting  the  fat  by  steaming  or  solvents, 
and  drying  and  grinding  into  powder.  It  is  usually  in 
excellent  mechanical  condition,  and  when  free  from  bone 
is  quite  uniform  in  composition,  containing  on  the  aver- 
age twelve  per  cent  of  nitrogen. 

Tankage.  —  Tankage  is  the  dried  refuse  from  slaughter- 
houses and  butcher-shops,  and  is  composed  of  various 
wastes  —  as  offal,  skin,  bone,  hair,  and  meat;  it  contains 
both  nitrogen  and  phosphoric  acid,  though  usually  classed 
as  a  nitrogenous  product. 

The  source  from  which  this  material  is  derived  indicates 
at  once  that  it  must  be  variable  in  composition  ;  it  shows 
wide  ranges  in  its  content  of  both  nitrogen  and  phosphoric 
acid.  These  variations  in  composition  are  largely  due  to 
the  quantity  of  bone  contained  in  it.  The  larger  the  pro- 
portion of  bone,  the  lower  the  percentage  of  nitrogen,  and 
the  smaller  the  proportion  of  bone,  the  higher  the  content 
of  nitrogen.     What  is  called  "concentrated  tankage"  is 


76  FIRST  PRINCIPLES  OF  AGRICULTURE. 

made  up  more  largely  of  extractive  animal  matter,  and 
is  more  uniform  in  composition,  and  much  richer  in 
nitrogen. 

The  lack  of  uniformity  in  both  the  chemical  composition 
and  physical  character  of  tankage,  makes  it  impossible  to 
give  to  it  a  distinct  position  as  a  fertilizing  product,  since 
the  results  derived  from  its  use  under  uniform  conditions 
in  other  respects  must  naturally  be  variable. 

Dried  Fish.  —  Dried  fish  was  formerly  an  important 
and  considerable  source  of  organic  nitrogen.  It  is  derived 
mainly  from  the  waste  resulting  from  the  extraction  of 
the  oil  from  the  menhaden,  a  fish  not  used  for  food,  though 
valuable  for  this  purpose.  The  waste  from  fish-canning 
establishments  also  furnishes  a  considerable  amount  of 
this  product. 

The  "  menhaden  pomace "  is  rich  in  quickly  available 
nitrogen,  and  also  contains  considerable  phosphoric  acid, 
derived  from  the  bone  contained  in  it;  it  is  reasonably 
uniform  in  composition.  The  waste  from  the  canneries 
contains  more  of  the  skin  and  bone,  and  is  more  variable 
in  composition.  Aside  from  the  source  from  which  it  is 
derived,  the  chief  cause  of  variability  in  composition  is  the 
content  of  water.  Frequently,  too,  acid  is  used  to  prevent 
decomposition,  which,  while  useful  in  making  the  constitu- 
ents more  available,  renders  the  product  less  concentrated 
and  less  easily  dried.  Well-dried  samples  contain  on  the 
average  seven  to  eight  per  cent  of  nitrogen,  and  the  same 
of  phosphoric  acid.  Finely  ground,  it  decays  rapidly  in 
the  soil,  and  is  highly  regarded  as  a  manure. 

Fish  was  one  of  the  first  materials  used  as  a  fertilizer. 
The  custom  in  this  country  in  early  times,  of  using  a  fish 


ARTIFICIAL  AND   CONCENTRATED  MANURES.     77 

in  each  hill  of  corn,  is  still  practised  in  regions  near  the 
sea  where  they  are  easily  procured. 

Leather  Meal.  —  This  material,  already  described  in  a 
previous  chapter,  is  frequently  treated  by  various  proces- 
ses, in  order  to  render  its  nitrogen  more  available.  Chief 
among  these  are  heating  to  a  high  temperature,  and  steam- 
ing, which  change  its  original  form  and  structure,  making 
it  mealy  and  crumbly.  Methods  of  treating  with  borax 
and  benzine,  and  dissolving  in  sulphuric  acid,  are  also 
practised.  Experiments  have  shown  that  all  of  these 
processes  aid  materially  in  improving  the  quality  of  the 
nitrogen  in  this  product. 

Horn  and  Hoof  Meal.  — These  materials  are  rich  in 
nitrogen,  and  are  quite  uniform  in  composition,  though  in 
their  original  condition  they  are  slow  to  decay.  They 
are  frequently  treated  in  somewhat  the  same  manner  as 
leather,  in  order  to  render  the  constituent  nitrogen  more 
directly  available  to  plants. 

Thus,  while  these  products,  containing  a  high  content  of 
nitrogen  in  very  slowly  available  forms,  do  have  some  value, 
it  is  doubtful  whether  their  use,  either  in  their  original  or 
treated  form,  is  advisable,  except  when  they  can  be  pur- 
chased at  a  much  lower  price  per  pound  than  in  forms 
of  known  value. 

Cottonseed  Meal.  —  A  few  vegetable  waste  products 
contain  sufficient  nitrogen  to  warrant  their  use  as  concen- 
trated manures.  Among  these  cottonseed  meal  is  probably 
used  to  the  greatest  extent.  The  cottonseed  is  first  hulled, 
ground  and  steamed,  and  the  oil  extracted.  It  is  quite 
uniform  in  its  composition,  and  contains  on  the  average 
six  and  eight-tenths  per  cent  of  nitrogen.     Its  value  as 


78  FIRST  PRINCIPLES  OF  AGRICULTURE. 

a  food  for  stock,  however,  limits  its  use  as  a  fertilizer 
at  points  distant  from  place  of  production.  It  is  fine  and 
dry,  and  decays  rapidly  in  the  soil,  and  is  regarded  as  one 
of  the  best  forms  of  organic  nitrogen. 

Castor  Pomace.  —  Castor  pomace  is  similar  to  cotton- 
seed meal,  both  in  its  composition  and  in  the  quality  of  its 
nitrogen.  It  is  the  refuse  castor  bean  after  the  oil  has 
been  extracted.  It  is  not  an  important  source  of  organic 
nitrogen,  though  practically  the  whole  product  is  used  as 
a  manure. 

Organic  Nitrogenous  Materials  are  Variable. — As 
has  been  indicated,  organic  nitrogenous  materials  are,  on 
the  whole,  variable  products,  both  in  respect  to  their 
content  of  nitrogen,  and  to  its  availability.  Those  that 
are  uniform  in  respect  to  their  composition  are  more  valu- 
able than  the  others,  since  their  availability  may  be  tested, 
and  an  average  arrived  at. 

Those  high-grade  products,  like  dried  blood,  azotine, 
dried  fish,  and  cottonseed  meal,  which  are  fairly  uniform 
in  these  respects,  show,  both  by  chemical  and  field  tests, 
a  high  percentage  of  availability,  which  does  not  vary 
greatly  with  different  samples  ;  while  those  like  tankage 
sometimes  show  a  high  and  sometimes  a  low  availability, 
because  of  the  lack  of  uniformity  in  the  proportions  of 
their  component  parts. 

The  Use  of  Nitrogen.  —  Great  care  should  be  exercised 
in  the  purchase  and  use  of  nitrogen,  first,  because  it  is  an 
expensive  element ;  and  second,  because  when  it  is  in  a  form 
useful  to  plants  it  is  entirely  soluble  in  water  and  freely 
movable,  and,  therefore,  liable  to  be  washed  away  and  lost. 
The  other  elements,  phosphoric  acid  and  potash,  cost  much 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     79 

less  than  nitrogen,  and  are  fixed  in  the  soil,  and,  as  a  rule, 
are  taken  out  of  the  soil  only  by  the  plants  themselves.  It 
is  estimated  that,  even  when  the  greatest  care  is  exercised, 
not  more  than  two-thirds  of  the  nitrogen  applied  as  manure 
is  used  by  the  crop.  Carelessness  in  its  use  results,  of 
course,  in  much  greater  losses. 

Application  of  Nitrates.  —  Nitrates  being  completely 
soluble,  should  not  be  applied  in  large  quantities  in  the  fall 
of  the  year,  or  in  the  early  spring  before  vegetation  begins. 
The  most  economical  use  of  this  form  of  nitrogen  lies  in 
its  fractional  application  to  growing  crops  in  quantities 
sufficient  for  their  needs.  An  overabundance  of  available 
nitrogen  frequently  causes  a  too  rapid  development  of  leaf. 
It  should  be  applied  when  the  foliage  is  dry,  either  pre 
ceding  or  following  a  rain,  in  order  to  effect  its  solution, 
unless  it  is  cultivated  into  the  surface  soil.  The  favorable 
effect  of  nitrates  applied  in  this  way  is  very  quickly 
noticeable,  especially  upon  vegetable  and  garden  crops. 

The  above  is  true,  though  in  a  less  degree,  of  am- 
monia salts.  Frequently  losses  occur  through  too  heavy 
applications  at  the  wrong  time. 

Application  of  Organic  Nitrogen.  —  Organic  forms 
of  nitrogen  may  be  applied  at  any  time,  and  in  larger 
quantities.  The  more  insoluble  materials  should  be  ap- 
plied in  amounts  known  to  be  in  excess  of  the  needs 
of  the  crop;  since,  even  under  the  best  conditions,  the 
nitrogen  contained  in  them  is  slowly  available. 

Materials  like  blood  and  fine-ground  fish  will  rot  com- 
pletely in  an  average  season ;  while  horn,  hoof,  hair, 
leather,  wool,  etc.,  may  require  several  seasons  to  effect 
their  complete  decay. 


80  FI118 T  PRINCIPLES   OF  AGRICULTURE. 


CHAPTEE  VII. 
Artificial  and  Concentrated  Manures;  Phosphates. 

The  phosphoric  acid  in  artificial  manures  is  derived 
from  compounds  called  "phosphates."  In  phosphates 
the  phosphoric  acid  is  united  with  lime,  iron,  and  alu- 
mina, forming  phosphates  of  lime,  iron,  and  alumina,  as 
the  case  may  be.  The  phosphates  of  lime  are  better 
calculated  for  the  purpose,  and  are,  therefore,  used  more 
largely  than  any  other  as  a  source  of  phosphoric  acid 
in  the  manufacture  of  artificial  manures. 

The  phosphates  available  for  this  purpose  are  not, 
however,  pure  salts,  but  exist  in  combination  either  with 
organic  substances,  or  with  minerals,  or  both ;  the  con- 
tent of  phosphoric  acid  and  its  combination  with  other 
substances  determining  the  usefulness  of  the  phosphate 
to  the  manure-maker. 

The  phosphoric  acid  in  these  materials  is  difficultly 
soluble  in  the  soil  water ;  and  hence  in  their  original  con- 
dition, or  in  the  crude  raw  forms,  they  give  up  this  ele- 
ment in  proportion  as  they  decompose  or  decay  in  the 
soil.  Those  in  combination  with  organic  substances, 
either  animal  or  vegetable,  are,  as  a  rule,  more  quickly 
useful  as  a  source  of  phosphoric  acid  than  those  com- 
posed entirely  of  mineral  constituents. 

Animal  Bone.  —  The  bones  of  animals  are  the  chief 
source  of  phosphates  that  exist  in  combination  with  or- 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     81 

ganic  matter,  and  were  for  a  long  time  the  main  source 
for  manurial  purposes. 

Bone  consists  chiefly  of  three  classes  of  substances; 
viz.,  moisture,  organic  matter,  containing  nitrogenous  and 
fatty  matter,  and  phosphate  of  lime,  —  the  proportion, 
particularly  of  the  nitrogen  and  phosphoric  acid,  depend- 
ing upon  the  kind  of  bone,  and  the  method  of  its  treat- 
ment. 

Bone  from  the  same  kind  of  animal  differs  in  compo- 
sition according  to  the  age  of  the  animal,  and  according 
to  its  location  in  the  body.  In  a  general  way  the  younger 
the  animal  the  softer  the  bone,  the  poorer  in  phosphate 
of  lime,  and  the  richer  in  nitrogen;  the  older  the  animal, 
the  richer  in  phosphate  of  lime,  and  the  poorer  in  nitro- 
gen. The  large  and  hard  thigh  bones  of  an  ox,  for  in- 
stance, differ  in  composition  from  the  softer  and  more 
porous  bones  of  other  parts  of  the  body. 

Treat  a  bone  with  dilute  hydrochloric  acid,  and  you 
dissolve  the  phosphate  of  lime,  and  leave  the  soft  pulpy 
animal  matter,  which  retains  its  original  shape.  Burn 
the  bone,  and  you  drive  off  the  organic  matter,  and  leave 
the  porous  phosphate  of  lime  in  the  original  shape,  show- 
ing the  structure  of  the  bone.  The  phosphate  of  lime 
of  the  harder  bones  is  dense  and  compact ;  that  from 
the  softer  bone  is  more  open  and  porous.  The  chief  cause 
of  variation  in  the  composition  of  bones  used  as  manure, 
however,  is  due  to  the  treatment  they  receive.  This  is 
recognized  by  manufacturers  and  dealers,  and  different 
names  of  brands  are  used  to  indicate  the  method  of 
manufacture  or  treatment;  as  applied,  however,  they  do 
not  always  correspond  to  the  methods  of  treatment. 


82  FIRST  PRINCIPLES  OF  AGRICULTURE. 

Raw  Bone.  —  The  term  "  raw  bone "  is  properly  ap- 
plied to  bone  that  has  not  suffered  any  loss  of  its  origi- 
nal constituents  in  the  processes  of  its  manufacture ;  and 
is  for  this  reason  highly  regarded  by  farmers,  who  be- 
lieve that  it  is  purer  than  any  other  form.  This  is 
true  in  a  large  measure,  though  the  fact  that  it  is  raw 
bone  is  not  altogether  an  advantage  from  the  standpoint 
of  usefulness.  Raw  bone  too  often  contains  consider- 
able fatty  matter,  which  makes  it  a  difficult  process  to 
grind  it  fine,  and  which  also  has  a  tendency  to  retard  the 
decay  of  the  bone  in  the  soil.  A  considerable  amount  of 
fat  also  reduces  proportionately  the  percentage  of  the  val- 
uable constituents,  phosphoric  acid  and  nitrogen.  Good 
raw  bone,  free  from  meat  and  excess  of  fat,  should  con- 
tain on  the  average  twenty-two  per  cent  of  phosphoric 
acid,  and  four  per  cent  of  nitrogen. 

Pine  Bone.  —  The  trade  terms  "bone  meal,"  "bone 
dust,"  and  "fine  bone"  are  used  to  indicate  mechanical 
condition,  or  fineness  of  division,  and  do  not  refer  es- 
pecially to  composition.  These  names  should  not  be 
taken  as  indicating  the  fineness  without  personal  exami- 
nation, since  frequently  the  products  do  not,  in  this 
respect,  correspond  to  the  name.  Fineness  is  an  impor- 
tant consideration,  since,  the  finer  the  bone,  the  quicker  it 
will  decay,  and  its  constituents  become  available  to  plants. 

Boiled  and  Steamed  Bone.  —  The  larger  portion  of 
the  bone  used  as  manure  has  been  boiled  or  steamed  for 
the  purpose  of  freeing  it  from  fat  and  nitrogenous  matter, 
both  of  which  are  products  valuable  for  other  purposes. 
The  fat  is,  of  course,  of  no  value  as  a  manure,  and  its 
absence   is   an   advantage.      The   nitrogen,   while   useful 


ARTIFICIAL  AND   CONCENTRATED  MANURES.     83 

as  a  manure,  is  extracted  chiefly  for  the  purpose  of  mak- 
ing glue  and  gelatine. 

By  boiling  or  steaming,  the  bone  suffers  a  loss  of  its 
original  constituents,  the  chief  result  of  which  is  to 
change  the  proportions  of  the  nitrogen  and  phosphoric 
acid  contained  in  it.  Steamed  or  boiled  bone  contains 
more  phosphoric  acid,  and  less  nitrogen,  than  raw  bone, 
and  is  also  more  variable  in  composition,  the  relative 
percentage  of  these  constituents  depending  upon  the  de- 
gree of  steaming  or  boiling  to  which  the  bone  has  been 
subjected. 

Bone  that  has  been  used  for  the  purpose  of  making 
glue,  where  the  chief  object  is  to  extract  the  nitrogenous 
matter,  contains  from  twenty-eight  to  thirty  per  cent  of 
phosphoric  acid,  and  from  one  and  one-quarter  to  one 
and  three-quarters  per  cent  of  nitrogen.  The  steaming  of 
bone,  particularly  when  conducted  at  high  pressure,  also 
exerts  a  favorable  effect  upon  the  physical  and  mechani- 
cal character  of  the  bone.  It  destroys  its  original  struc- 
ture, makes  it  soft  and  crumbly,  and  often  reduces  it  to 
a  finer  state  of  division  than  can  be  readily  accomplished 
by  grinding;  and,  since  it  is  also  free  from  fat,  and  is 
finer,  it  is  more  directly  useful  as  a  source  of  phosphoric 
acid  to  plants  than  purer  raw  bone. 

Experiments  have  shown  that  the  phosphoric  acid  in 
fine  steamed  bone  may  all  become  available  in  the  soil, 
under  average  conditions,  in  one  or  two  seasons ;  while 
that  in  the  coarser,  fatty  raw  bone  is  not  completely  used 
in  three  or  four  years,  and  sometimes  longer. 

In  some  cases,  the  fat  is  extracted  from  bone  by  means 
of  such  solvents  as  petroleum  or  benzine.     These  meth- 


84  FIRST  PRINCIPLES   OF  AGRICULTURE. 

ods  of  extracting  the  fat  have  the  advantage  of  increas- 
ing the  relative  proportion  of  the  nitrogen,  this  element 
not  being  attacked  by  the  solvents. 

The  more  complete  extraction  of  the  fat  and  moisture 
by  these  methods  also  aids  in  the  final  preparation  of  the 
bone  by  grinding.  Bone  prepared  in  this  way  frequently 
contains  as  high  as  six  per  cent  of  nitrogen,  and  twenty 
per  cent  of  phosphoric  acid. 

The  nature  and  composition  of  animal  bone  is  such  as 
to  make  it  a  valuable  source  of  phosphoric  acid;  and, 
while  it  is  largely  used  with  nitrogenous  and  potassic 
materials  in  the  manufacture  of  artificial  manures,  its 
best  use  is,  perhaps,  in  the  fine  ground  form,  particularly 
for  soil  improvement  and  for  slow-growing  crops. 

Phosphoric  acid  applied  in  this  form  gradually  gives 
up  nitrogen  and  phosphoric  acid  to  the  plant ;  and  its 
physical  and  chemical  conditions  are  such  that  it  forms 
in  the  soil,  during  the  growing  season,  no  compounds 
more  insoluble  than  the  bone  itself.  Of  all  the  phos- 
phatic  materials  available  as  manure,  bone  is  the  only 
one  that  is  now  used  to  any  extent  without  further  treat- 
ment than  simple  grinding. 

Bone-black  or  Animal  Charcoal.  —  This  material 
becomes  an  important  source  of  phosphoric  acid  for  arti- 
ficial manures  after  it  has  served  its  chief  and  first  pur- 
pose in  clarifying  sugar.  In  making  bone-black  only  the 
best  bones  are  used;  they  are  cleaned  and  dried,  and 
placed  in  air-tight  vessels,  and  heated  until  all  volatile 
matter  is  driven  off;  the  resultant  product,  which  retains 
in  part  the  original  form  of  the  bone,  is  then  ground  to 
a  coarse  powder ;  it  then  becomes  a  bone  charcoal,  con- 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     85 

sisting  chiefly  of  carbon  and  phosphate  of  lime,  though 
also  containing  small  amounts  of  magnesia  and  carbonate 
of  lime. 

Bone-black,  as  received  from  the  refineries,  contains  the 
impurities  gathered  there,  consisting  chiefly  of  vegetable 
matter  and  moisture.  It  is  somewhat  variable  in  compo- 
sition, containing  from  thirty-two  to  thirty-six  per  cent 
of  phosphoric  acid  and  a  small  amount  of  nitrogen.  It 
decays  slowly  in  the  soil,  and  is  not  now  used  to  any 
extent  directly  as  a  manure. 

Bone-ash.  —  Bone-ash,  though  not  a  large,  is  an  ex- 
cellent source  of  phosphoric  acid.  It  is  exported  in  con- 
siderable quantities  from  South  America,  where  the  bones 
are  burned,  and  the  bulk  reduced,  in  order  to  facilitate 
transportation.  It  does]  not  contain  nitrogen,  and  is  more 
variable  in  composition  than  bone-black,  though  usually 
somewhat  richer  in  phosphate  of  lime.  Good  samples 
contain  from  twenty-seven  per  cent  to  thirty-six  per  cent 
of  phosphoric  acid. 

Bones  themselves,  and  the  phosphates  derived  from 
bones,  constitute  a  class  differing  from  other  phosphates 
used  in  making  manures,  in  that  they  are  derived  directly 
from  organic  materials ;  and,  as  a  class,  they  possess  char- 
acteristics due  to  this  fact,  which  render  them  more  use- 
ful than  those  derived  from  purely  mineral  sources. 

Mineral  Phosphates.  —  These  constitute  a  class  of 
products  differing  from  those  of  immediate  or  recent  ani- 
mal origin,  mainly  in  the  fact  that  they  are  not  combined 
with  organic  matter,  and  are  more  dense  and  compact  in 
their  structure.  They  occur  in  several  different  forms, 
and  are  procured  from  distinct  sources. 


86  FIRST  PRINCIPLES   OF  AGRICULTURE. 

South  Carolina  Rock  Phosphates.  — These  are  found 
both  on  the  land  and  in  the  beds  of  rivers  in  the  vicinity 
of  Charleston,  S.  C,  and  are  sometimes  called  "  Charles- 
ton Phosphates."  The  deposits  vary  in  thickness  from 
one  to  twenty  feet,  through  which  the  phosphate  is  dis- 
tributed in  the  form  of  lumps  or  nodules,  ranging  in 
weight  from  an  ounce  to  over  a  ton.  These  nodules 
are  irregular,  non-crystalline  masses,  often  full  of  holes, 
which  contain  clay  or  other  non-phosphatic  materials. 
That  obtained  from  the  river  is  called  "  river  phosphate," 
or  "  river  rock ; "  and  that  from  the  land,  "  land  phos- 
phate," or  "  land  rock."  The  two  varieties  do  not  dif- 
fer materially  in  composition,  particularly  in  the  content 
of  phosphoric  acid. 

The  rock  contains  from  twenty-six  per  cent  to  twenty- 
eight  per  cent  of  phosphoric  acid.  Its  uniformity,  in 
connection  with  the  fact  that  it  contains  but  small  per- 
centages of  compounds  of  iron  and  alumina,  minerals 
which  prevent  its  best  use  by  the  manufacturer,  makes 
it  a  highly  satisfactory  source  of  phosphoric  acid. 

The  river  rock  is  secured  by  dredging;  that  from  the 
land  is  largely  dug.  In  either  case,  it  is  washed  to 
remove  the  adhering  matter,  and  then  dried,  when  it  is 
ready  for  grinding  or  shipment.  South  Carolina  rock 
phosphate,  when  very  finely  ground,  is  called  "floats." 
It  is  sometimes  used  upon  the  land  in  this  form. 

These  deposits  were  first  worked  in  1868,  though  the 
presence  of  phosphate  at  this  point  was  known  at  a 
much  earlier  date. 

Florida  Phosphates.  —  The  presence  of  phosphate  in 
commercial  quantities  in  Florida  was  discovered  in  1888, 


ARTIFICIAL  AND   CONCENTRATED  MANURES.      87 

since  which  time  very  great  progress  has  been  made  in 
developing  the  deposits.  These  deposits  occur  in  a  num- 
ber of  forms,  —  first,  "  soft  phosphate,"  a  whitish  product, 
somewhat  resembling  clay,  and  largely  contaminated  with 
it ;  second,  "  pebble  phosphate,"  consisting  of  hard  peb- 
bles, occurring  both  in  river-beds  and  upon  the  land,  and 
mixed  with  other  materials ;  and  third,  "  rock,"  or  "  bowl- 
der phosphate,"  which  occurs  in  the  form  of  stony  masses, 
or  bowlders,  both  large  and  small.  These  three  forms 
also  differ  widely  in  composition,  both  in  reference  to 
their  content  of  phosphoric  acid  and  in  respect  to  the 
presence  of  other  minerals. 

The  soft  phosphate  is  the  poorest  in  phosphoric  acid : 
it  is  easily  prepared,  and  is  largely  used  directly  upon 
the  land ;  it  is  also  the  most  variable  in  composition, 
ranging  from  eighteen  to  thirty  per  cent.  The  pebble 
rock  is  also  variable  in  composition,  though,  when  washed 
free  of  sand  and  clay,  it  is  richer  in  phosphoric  acid 
than  the  soft  variety;  good  samples  contain  as  high  as 
forty  per  cent  and  over  of  phosphoric  acid.  The  bulk 
of  the  "Florida  Phosphate"  is  believed  to  exist  in  the 
pebble  form. 

The  rock  or  bowlder  phosphate,  though  apparently 
much  less  in  amount,  is  more  uniform  in  composition, 
and  is  much  richer  than  either  of  the  other  forms.  The 
clean,  dry  bowlder  phosphate  often  contains  as  high  as 
forty  per  cent  phosphoric  acid,  far  exceeding  in  richness 
the  South  Carolina  rock  superphosphate. 

Canadian  Apatite.  —  This  material  is  a  crystallized 
rock  of  true  mineral  origin,  and  occurs  associated  to  a 
greater  or  less  extent  with  other  materials.     It  is,  there- 


88  FIRST  PRINCIPLES   OF  AGRICULTURE. 

fore,  not  uniform  in  character,  the  phosphoric  acid  vary- 
ing according  to  the  amount  of  the  other  substances 
present. 

It  is  mined  in  the  provinces  of  Quebec  and  Ontario, 
and  separated  into  various  grades  at  the  mines.  The 
mining  is  expensive,  and  the  necessity  for  grading  in 
addition  makes  the  cost  of  production  proportionately 
high.  The  highest  grade  of  this  phosphate  is  very  pure, 
containing  forty  per  cent  of  phosphoric  acid. 

Iron  Phosphate.  —  This  is  a  waste  product  from  the 
manufacture  of  steel  from  phosphatic  iron  ores,  by  what 
is  known  as  the  "  basic  process."  It  is  sold  under  several 
names,  as  "  Thomas  Phosphate  Meal,"  "  Phosphate  Slag," 
"  Basic  Slag,"  and  "  Odorless  Phosphate."  It  is  produced 
in  large  quantities  in  England,  Prance,  and  Germany ;  and 
in  those  countries  is  not  only  one  of  the  cheapest  sources 
of  phosphoric  acid,  but  is  regarded  as  a  very  valuable 
product.  It  is  not  produced  to  any  extent  in  America, 
is  known  under  the  name  of  "Odorless  Phosphate,"  and 
is  not  largely  used.  It  contains  from  fifteen  to  twenty 
per  cent  of  phosphoric  acid,  in  the  form  of  phosphate 
of  lime,  in  connection  with  large  amounts  of  lime  and 
oxide  of  iron.  It  is  used  almost  altogether  in  the  form 
of  a  fine  powder,  since  it  is  not  suitable  for  the  purposes 
of  the  manufacturer.  When  very  finely  ground,  the 
phosphoric  acid  is  quite  as  active  as  that  contained  in 
fine  bone  meal,  and  is  especially  suitable  for  clay  and 
sandy  soils  and  for  meadows. 

Phosphatic  Guanos.  —  Previous  to  the  discovery  of 
the  phosphates  in  South  Carolina,  these  guanos  were  a 
very  important  source  of  phosphoric  acid;  they  are  now 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     89 

but  little  used  in  this  country.  They  are  obtained  from 
the  rainless  districts  of  the  world,  chiefly  from  the 
islands  bordering  the  coast  of  South  America  and  from 
the  West  Indies.  They  are  derived  from  the  excrements 
of  birds,  and  frequently  contain  considerable  organic 
matter  containing  nitrogen. 

The  Peruvian  guano  of  earlier  times  was  particularly 
rich  in  the  best  forms  of  nitrogen.  The  purely  phos- 
phatic  guanos  are  rich  in  phosphoric  acid,  and  are  excel- 
lent materials;  like  the  iron  phosphate,  they  are  not 
suitable  for  the  manufacture  of  artificial  manures. 

Insolubility  of  Phosphates.  —  The  phosphates  men- 
tioned constitute  what  are  called  "raw  materials,"  and, 
with  the  exception  of  bone,  are  not  largely  used  directly, 
or  without  further  treatment  to  render  the  phosphoric 
acid  more  soluble,  and  thus  more  immediately  available 
to  plants.  As  already  stated,  the  phosphoric  acid  in 
them  becomes  food  in  proportion  to  the  rapidity  of  de- 
cay, which  is  influenced  both  by  the  character  of  the 
material  and  the  fineness  of  its  division.  Fine  mate- 
rials, too,  permit  of  a  more  even  distribution,  thus  bring- 
ing more  particles  of  phosphate  in  contact  with  the 
roots  of  the  plants. 


90  FIRST  PRINCIPLES   OF  AGRICULTURE. 


CHAPTER  VIH. 

Artificial  and  Concentrated  Manures ;  Superphosphates  and  Potash 

Salts. 

Phosphate  of  lime  is  a  chemical  salt  capable  of  exist- 
ing in  three  forms.  The  first  consists  of  three  parts  of 
lime  and  one  part  of  phosphoric  acid;  this  is  the  insolu- 
ble form,  and  it  exists  as  such  in  all  natural  phosphates. 
This  form,  because  of  the  three  parts  of  lime  contained 
in  it,  is  also  called  "tricalcic,"  "tribasic,"  or  "three- 
lime  phosphate."  The  second  form  consists  of  two  parts 
of  lime  and  one  of  phosphoric  acid,  and  is  called  "dical- 
cic,"  "  dibasic,"  or  "  two-lime  phosphate  ; "  it  is  insoluble 
in  water,  but  readily  soluble  to  the  roots  of  plants.  The 
third  form  consists  of  one  part  of  lime  and  one  of  phos- 
phoric acid,  and  is  called  " monocalcic,"  "monobasic," 
"acid  phosphate,"  or  "superphosphate."  This  form  is 
completely  soluble  in  water,  readily  distributes  itself 
everywhere  in  the  soil,  and  is  immediately  available  to 
plants.  A  " tetrabasic,"  or  "four-lime  phosphate,"  has 
been  found  in  basic  slag.  This  form,  though  insoluble 
in  water,  breaks  up  readily  and  is  more  available  than 
the  insoluble  "tribasic"  form. 

Superphosphates,  or  soluble  phosphates,  are  made  from 
the  raw  materials  containing  insoluble  tricalcic  phos- 
phate,  by  first    grinding   them    to  a   powder   and   then 


ARTIFICIAL  AND   CONCENTRATED  MANURES.     91 

mixing  them  with  sulphuric  acid,  which  changes  the 
tricalcic  —  three-lime  —  into  the  monocalcic  —  one-lime 
—  form,  or  the  insoluble  into  the  soluble  form.  In  this 
process,  two  of  the  three  parts  of  the  lime,  combined 
with  the  phosphoric  acid  to  form  the  insoluble  phos- 
phate, are  removed  and  united  to  sulphuric  acid,  forming 
sulphate  of  lime,  leaving  one  part  of  lime  combined  with 
phosphoric  acid,  which  is  the  "monocalcic"  or  "super- 
phosphate." 

A  pure  superphosphate  is,  therefore,  a  mixture  of  a 
soluble  phosphate,  and  of  sulphate  of  lime,  or  gypsum. 

Soluble  Phosphoric  Acid.  —  Nearly  all  workable  pro- 
ducts containing  phosphate  of  lime  are  capable  of  being 
converted  into  an  "  acid  phosphate  "  or  a  "  superphos- 
phate." The  soluble  phosphoric  acid  thus  obtained  is  a 
definite  compound,  and  is  identical  in  composition,  from 
whatever  source  derived. 

The  term  "phosphate"  is  applied  to  any  material  con- 
taining, as  its  chief  constituent,  phosphoric  acid.  The 
term  "  superphosphate "  is  applied  to  any  material  con- 
taining soluble  phosphoric  acid  as  its  chief  constituent. 

Thus  we  have  the  phosphates  already  described,  which 
when  treated  with  sulphuric  acid  are  converted  into 
superphosphates,  as  bone  superphosphate,  South  Carolina 
rock  superphosphate,  bone-black  superphosphate,  bone- 
ash  superphosphate,  and  Florida  rock  superphosphate. 
Care  should  be  taken  not  to  confound  the  terms  "  phos- 
phate "  and  "  superphosphate."  They  are,  as  we  have 
seen,  very  different  both  in  composition  and  character. 

Composition  of  Superphosphates.  —  Superphosphates 
differ  in  their  content  of  phosphoric  acid  according  to  the 


92  FIRST  PRINCIPLES  OF  AGRICULTURE. 

composition  and  character  of  the  phosphates  from  which 
they  are  made.  Those  made  from  organic  phosphates,  as 
bone  black  and  bone  ash,  are  richer  in  soluble  phosphoric 
acid  than  those  made  from  animal  bone  or  from  mineral 
phosphates;  since  these  materials  are  of  such  a  character 
as  to  enable  the  manufacturer  to  add  sufficient  sulphuric 
acid  to  convert  all  of  the  phosphate  present  into  a  soluble 
form,  and  at  the  same  time  to  secure  a  dry  fine  product, 
which  is  an  important  consideration  in  making  super- 
phosphates. 

Mineral  phosphates,  both  because  of  their  hardness  and 
of  the  presence  of  other  minerals  which  are  attacked  by 
the  acid,  are  less  easily  dissolved,  and  require  more  acid 
in  proportion  to  the  phosphate  present  than  those  from 
organic  sources.  They  are  also  less  absorbent,  hence  it  is 
more  difficult  to  secure  good  condition  when  sufficient  acid 
is  used  to  dissolve  all  the  phosphate.  In  making  super- 
phosphates from  these  materials,  less  acid  is  used  than 
is  required  to  completely  dissolve  the  phosphates ;  and 
there  is,  therefore,  always  present  in  them  more  or  less 
of  the  insoluble  phosphoric  acid. 

In  the  case  of  animal  bone,  too,  less  sulphuric  acid  is 
used  than  is  required  to  completely  dissolve  the  phosphoric 
acid;  otherwise,  a  gummy,  sticky  product  would  result, 
due  largely  to  the  organic  matter  in  the  bone.  The  in- 
soluble phosphoric  acid  in  bone,  bone-black,  and  bone-ash 
superphosphates  is,  however,  of  greater  value  than  the 
insoluble  in  the  mineral  phosphates,  for  reasons  already 
given. 

In  superphosphates,  too,  there  is  nearly  always  present 
a  greater  or  less  amount  —  depending  upon  the  material  — 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     93 

of  the  second  form  of  phosphoric  acid,  the  dicalcic,  also 
called  "reverted"  or  "retrograde."  This  form  exists  in 
the  greatest  amounts  in  those  made  from  mineral  phos- 
phates, which  is  believed  to  be  due  either  to  the  soluble 
acting  upon  the  insoluble  portions,  or  to  the  presence  of 
oxide  of  iron  and  alumina,  which  combine  with  a  portion 
of  the  soluble  phosphoric  acid.  The  soluble  goes  back  to 
a  less  soluble  form. 

In  stating  the  composition  of  superphosphates,  the  three 
forms  of  phosphoric  acid  are  all  recognized.  The  sum  of 
the  soluble  and  reverted  is  called  the  "  total  available," 
because  these  forms  are  regarded  as  immediately  useful 
to  the  plant. 

Bone  ash  and  bone  black  contain  on  the  average  sixteen 
per  cent  of  total  available  phosphoric  acid,  practically  all 
soluble ;  while  those  from  mineral  sources  usually  contain 
less  than  fourteen  per  cent  total  available,  which  includes 
one  to  three  per  cent  of  dicalcic  or  reverted.  These  also 
contain  from  one  to  three  per  cent  of  insoluble  phosphoric 
acid. 

Superphosphates  made  from  animal  bone  are  more  vari- 
able in  their  composition  than  those  made  from  bone 
black  or  the  mineral  phosphates;  this  being  due  largely 
to  the  variability  of  the  raw  materials,  chiefly  in  respect 
to  the  content  of  phosphoric  acid.  These  differ,  too,  from 
the  others  mentioned  in  containing  nitrogen  in  addition 
to  the  phosphoric  acid ;  for  this  reason  they  are  fre- 
quently called  "  ammoniated  superphosphates,"  or  dis- 
solved ammoniated  bone. 

Advantages  of  Soluble  Phosphoric  Acid.  —  Soluble 
phosphoric  acid,  in  addition  to  its  direct  availability,  which 


94  FIRST  PRINCIPLES  OF  AGRICULTURE. 

is  its  first  advantage,  is  chiefly  valuable  because  of  its  ease 
of  self-distribution.  When  applied  to  the  soil,  it  is  taken 
up  by  the  water  and  more  generally  distributed  than  is 
possible  by  any  mechanical  means,  however  fine  the  sub- 
stance may  be  ground.  The  roots  of  plants  come  in  con- 
stant contact  with  it  wherever  they  go. 

The  dicalcic  or  reverted  phosphoric  acid  is  believed  to 
be  quite  as  available  to  plants,  but  it  remains  exactly 
where  it  is  placed ;  if  the  roots  are  there  they  can  make 
quite  as  ready  use  of  it  as  the  soluble.  The  main  differ- 
ence between  the  soluble  and  reverted  is  that  in  the  former 
case  the  phosphoric  acid  goes  to  the  roots,  while  in  the 
latter  case  the  roots  must  go  to  the  phosphoric  acid.  The 
same  is  true  of  the  insoluble,  though  in  a  different  degree. 
Here  the  roots  must  not  only  go  to  the  phosphoric  acid,  but 
the  amount  that  can  be  used  is  measured  by  the  activity 
of  the  roots  in  aiding  its  solution. 

A  superphosphate,  therefore,  is  valuable  in  proportion  to 
the  amount  of  soluble  phosphoric  acid  contained  in  it ;  the 
greater  the  amount  of  soluble,  and  the  less  the  amount  of 
reverted  and  insoluble,  the  more  valuable.  If  insoluble  or 
reverted  forms  are  desired  —  and  they  are  often  quite  as 
useful  as  the  soluble  —  they  may  be  procured  from  un- 
treated products. 

Fixation  of  Phosphates. — Phosphoric  acid,  though 
soluble  in  water,  is  not  washed  from  the  soil ;  it  is  fixed 
there  by  combining  with  the  lime  and  other  minerals  pres- 
ent. It  is  believed  to  assume  first,  by  the  appropriation 
of  lime,  the  dicalcic  form,  though  it  is  not  positively  cer- 
tain that  the  insoluble  tricalcic  phosphate  is  not  sometimes 
formed.     It  may  also  combine  with  iron  and  alumina  and 


ARTIFICIAL  AND  CONCENTRATED  MANURES.      95 

form  phosphates ;  these  forms  are  believed  to  be  less 
readily  taken  up  by  the  plant  than  the  dicalcic  form. 

The  time  required  for  this  fixation,  as  well  as  the  form 
it  takes,  depends  upon  the  character  of  the  soil ;  though  on 
soils  in  a  good  state  of  fertility  the  fixation  is  quite  rapid. 
On  very  sandy  soils  the  fixation  is  sometimes  incomplete, 
because  of  the  absence  of  lime  and  iron. 

Use  of  Superphosphates.  —  Because  of  the  tendency 
of  soluble  phosphoric  acid  to  form  in  time  relatively  in- 
soluble compounds  in  the  soil,  it  is  often  recommended 
to  use  a  mixture  of  superphosphate  and  of  animal  bone, 
instead  of  either  alone;  the  soluble  for  immediate  use, 
and  the  less  soluble  for  use  at  later  stages  of  growth,  or 
for  the  improvement  of  fertility. 

Superphosphates  are  never  better  or  more  available 
than  when  applied ;  phosphates  are  probably  never  less 
available  than  at  the  time  applied. 

Recent  experiments  and  studies  show  that  fine  ground 
phosphates  are  very  desirable  under  certain  conditions, 
and  their  use  is  gradually  growing  in  favor.  This  point 
has  reference,  however,  to  the  economy  of  use,  which 
will  be  discussed  in  detail  in  its  proper  place. 

Potash  Manures.  —  Farm  crops  remove  considerable 
amounts  of  potash;  and  since  many  soils,  particularly 
those  composed  largely  of  sand,  are  not  rich  in  this  ele- 
ment, potash  becomes  a  very  important  constituent  of 
manures. 

In  the  early  history  of  the  country,  wood-ashes  were 
an  important,  and  practically  the  only,  source  of  potash 
for  manurial  purposes,  aside  from  yard  manure  and  vege- 
table  wastes.       At   the    present   time   by   far   the   most 


96  FIRST  PRINCIPLES   OF  AGRICULTURE. 

important  source  of  potash  is  the  Stassfurt  mines  of 
Germany.  These  mines  consist  of  deposits  of  crude 
salts,  which  have  doubtless  been  formed  by  the  evapo- 
ration of  the  water  in  an  inland  sea.  They  have  been 
worked  since  1862 ;  and,  while  enormous  quantities  have 
been  removed,  the  extent  of  the  deposits  is  so  great 
as  to  appear  inexhaustible. 

These  salts,  as  mined,  contain  relatively  small  per- 
centages of  actual  potash,  and  considerable  quantities 
of  other  salts,  some  of  which  are  injurious  to  plants, 
though  a  number  of  the  crude  salts  are  used  directly 
upon  the  land. 

The  crude  products  of  the  mines,  shipped  and  sold  in 
this  country,  consist  chiefly  of  kainit  and  sylvinit,  and  the 
manufactured  products  are  muriate  of  potash,  sulphate  of 
potash,  and  sulphate  of  potash  and  magnesia. 

These  salts  are  all  completely  soluble  in  water,  and 
equally  available  as  sources  of  food  to  plants.  The 
forms  have  reference  mainly  to  the  effect,  good  or  bad, 
upon  the  growth  of  plants,  of  the  constituents  with 
which  the  potash  is  combined,  or  the  other  salts 
with  which  the  potash  is  associated.  Chlorides  are  be- 
lieved to  be  less  desirable  than  the  sulphates  for  cer- 
tain crops. 

Forms  of  Potash.  —  The  commercial  potash  salts 
used  are  of  two  distinct  chemical  forms,  —  one  in  which 
the  potash  is  combined  with  chlorine  to  form  chloride 
of  potassium,  or,  as  it  is  more  generally  called,  "muriate 
of  potash ; "  the  other  in  which  the  potash  is  combined 
with  sulphuric  acid  to  form  "  sulphate  of  potash." 

Kainit.  —  This   is   the    only   crude   product    that   is 


ARTIFICIAL  AND  CONCENTRATED  MANURES.     97 

largely  used  directly  upon  the  land.  It  is  composed  of 
a  number  of  salts,  chiefly  "sodium  chloride,"  or  ordi- 
nary salt,  "  magnesium  chloride,"  "  magnesium  sulphate," 
and  "  potassium  sulphate." 

Although  the  potash  in  kainit  is  in  the  form  of  a 
sulphate,  its  effect  is  quite  similar  to  that  derived  from 
the  use  of  muriate,  because  of  the  large  quantities  of 
chlorides  contained  in  it,  in  combination  with  magnesia 
and  soda.  It  is  not  rich  in  potash,  containing  on  the 
average  twelve  and  one-half  per  cent  of  actual  potash, 
or  potassium  oxide. 

Sylvinit.  —  This  is  a  crude  salt,  similar  to  kainit  in 
that  it  contains  relatively  small  amounts  of  actual  pot- 
ash, though  the  potash  in  sylvinit  exists  both  in  the 
form  of  a  sulphate  and  of  a  muriate,  or  chloride.  There 
is,  too,  in  this  salt  less  of  the  magnesia  compounds  than 
in  the  kainit.  Sylvinit  is  not  largely  exported  to  this 
country.  The  analyses  of  the  products  used  here  show 
an  average  of  sixteen  per  cent  actual  potash. 

Kainit  and  Sylvinit  as  Indirect  Manures.  —  These 
crude  salts  are  valuable  as  indirect  manures  in  that  the 
salts  present,  other  than  the  potash,  have  a  solvent  effect 
upon  other  soil  constituents,  particularly  phosphates ; 
they  also  aid  in  many  cases  in  improving  the  physical 
character  of  soils.  It  is  believed,  too,  that  the  magnesia 
contained  in  them  serves  as  direct  food  under  certain 
circumstances,  though  this  point  is  not  regarded  as  of 
great  importance. 

The  Application  of  Crude  Potash  Salts.  —  In  the 
use  of  these  forms  of  potash,  it  is  recommended  that 
their  application  should  precede  by  a  considerable  time 


98  FIRST  PRINCIPLES   OF  AGRICULTURE. 

the  planting  of  the  crop,  in  order  to  avoid  danger  to 
the  young  plant  from  an  excess  of  magnesia  salts, 
which  injure  the  tender  rootlets  of  plants,  and  also  that 
the  excess  of  chlorides,  which  sometimes  influence  un- 
favorably the  quality  of  the  produce,  may  be  washed 
from  the  surface  soil  by  the  rains. 

In  Germany,  where  the  use  of  these  potash  compounds 
has  received  most  careful  study,  their  application  is 
almost  invariably  made  in  the  fall  of  the  year,  or  upon 
the  crop  preceding  the  one  which  is  in  especial  need 
of  potash  fertilization.  In  this  country,  owing  to  our 
heavy  spring  rains,  an  early  spring  application  will 
doubtless  answer  quite  as  well  in  most  cases. 

Muriate  of  Potash.  —  This  salt  is  manufactured  from 
the  crude  forms,  and  is  the  richest  in  potash  of  the 
Stassfurt  products.  It  varies  in  composition  according 
to  the  method  of  manufacture,  the  commercial  products 
being  divided  into  three  grades.  The  grade  most  com- 
monly met  with  upon  the  markets  here  contains  about 
fifty  per  cent  actual  potash,  or  potassium  oxide.  The 
chief  impurity  is  common  salt,  or  sodium  chloride ;  the 
lower  the  content  of  potash,  the  higher  the  content  of 
sodium  salts.  This  form  of  potash  is  perhaps  more 
largely  used  than  any  other. 

Sulphate  of  Potash.  —  This  form  of  potash,  often 
called  "high-grade  sulphate,"  is  regarded  as  preferable 
to  the  "muriate"  for  many  crops,  particularly  sugar- 
beets,  tobacco,  potatoes,  and  fruit,  chiefly  because  of  its 
more  favorable  influence  on  the  quality  of  the  produce. 
It  is,  however,  more  expensive  than  the  muriate,  and  is 
not   so    largely  used   by  the   manure-makers.     Its  effect 


ARTIFICIAL  AND  CONCENTRATED  MANURES.    99 

upon  yield  is  not  believed  to  be  superior  to  the  muriate. 
Commercial  forms  of  sulphate  of  potash  contain  on  the 
average  fifty  per  cent  of  actual  potash. 

Double  Sulphate  of  Potash  and  Magnesia.  —  This 
product  is  similar  to  the  high-grade  sulphate  in  its 
effect.  It  contains,  in  addition  to  the  sulphate  of  pot- 
ash, over  thirty  per  cent  of  sulphate  of  magnesia.  The 
potash  contained  in  the  product,  as  usually  found,  is 
equivalent  to  about  twenty-six  per  cent  of  actual  pot- 
ash, though  lower  grades  are  made.  These  are  known 
under  the  name  of  "double  manure  salts."  The  mag- 
nesia is  regarded  as  of  considerable  value,  particularly 
in  potato  manures.  The  cost  of  potash  in  the  double 
sulphate  is  also  greater  than  in  the  muriate. 

Appearance  of  Potash  Salts.  —  Although  all  these 
products  exist  in  the  form  of  salts,  they  differ  in  appear- 
ance and  character.  The  sulphates  are  usually  in  the 
form  of  a  fine  powder,  in  color  ranging  from  nearly  white 
to  a  dirty  gray.  The  muriate  is  in  the  form  of  small, 
though  distinct  crystals,  varying  in  color  from  grayish 
white  to  light  brown.  The  kainit  is  composed  of  crys- 
tals, varying  in  color  from  white  to  dark  gray,  giv- 
ing the  ground  salt  a  rather  pepper-and-salt  appearance. 
Upon  standing,  all  of  these  salts  have  a  tendency  to 
become  hard,  though,  with  the  exception  of  kainit,  they 
are  easily  pulverized.  Kainit  often  becomes  very  hard, 
and  requires  regrinding  in  order  to  make  its  application 
possible. 

The  Uses  of  Potash  Salts.  —  Although  these  salts 
are  regarded  mainly  as  sources  of  potash  to  the  manure 
manufacturer,  their  direct  use  upon  the  land  is  increasing 


100         FIRST  PRINCIPLES   OF  AGRICULTURE. 

rapidly.  This  is  due  in  large  part  to  the  facts  that  they 
are  of  such  a  character  as  to  make  their  application,  and 
even  distribution,  a  comparatively  easy  matter ;  that  the 
quality  of  the  potash  is  not  improved  by  the  manufac- 
turer ;  and  that  on  many  soils  crops  respond  to  liberal 
applications  of  potash  alone.  The  crops  most  benefited 
are  potatoes,  white  and  sweet  meadow  grasses,  clover, 
and  orchard  fruits. 


ARTIFICIAL  MANURES   OR   FERTILIZERS.      101 


CHAPTER   IX. 

Artificial  Manures  or  Fertilizers ;  Methods  of  Baying ;  Valuation ; 
Formulas. 

The  fertilizing  materials  described  in  the  three  preced- 
ing chapters  are  the  raw  materials,  and  are  the  main 
sources  of  supply  of  plant-food  to  manufacturers  and  to 
farmers. 

Standard  High-Grade  Materials.  —  Such  materials 
as  nitrate  of  soda,  sulphate  of  ammonia,  dried  blood,  bone 
black,  and  South  Carolina  rock  superphosphates,  and  the 
various  potash  salts,  are  called  standard  products.  Dif- 
ferent samples  of  any  of  these  do  not  vary  widely  in 
their  composition,  and  those  of  the  same  kind  are  prac- 
tically uniform  in  their  action.  For  instance,  any  one  ton 
of  nitrate  of  soda  contains  practically  the  same  amount 
of  nitrogen  as  any  other  ton,  and  the  nitrogen  is  always 
in  the  form  of  a  nitrate. 

They  are  standard  because  they  can  be  depended  upon, 
both  in  respect  to  composition  and  form  of  the  essential 
element.  These  are  important  advantages  not  possessed 
by  the  natural  manures  or  fertilizing  materials  derived 
from  other  sources.  They  are  also  called  "  chemical "  or 
"high  grade,"  because  they  are  in  most  cases  chemical 
compounds,  and  because  they  furnish  those  particular  ele- 
ments in  their  most  concentrated  and  active  forms. 


102         FIRST  PRINCIPLES  OF  AGRICULTURE. 

Incomplete  and  Complete  Fertilizers.  —  Fertilizing 
materials  may  contain  but  one  or  two  of  the  essential  con- 
stituents, nitrogen,  phosphoric  acid,  and  potash.  Hence 
the  name  "incomplete  fertilizer"  is  sometimes  applied  to 
them,  signifying  that  they  do  not  serve  in  all  cases  to 
supply  the  probable  needs  of  the  crop. 

The  fertilizers  manufactured  from  raw  materials  usually 
contain  all  three  of  these  essential  constituents ;  hence 
they  are  called  "  complete  fertilizers,"  signifying  that  they 
completely  meet  the  needs  of  the  crop  in  reference  to  the 
number  of  the  constituents  that  are  liable  to  be  lacking. 

Methods  of  Buying.  —  In  buying  a  fertilizer,  that 
which  gives  direct  value  is  the  fertilizing  constituent, 
nitrogen,  phosphoric  acid,  or  potash ;  hence  the  transac- 
tion is  virtually  the  buying  of  one  or  more  of  these  con- 
stituents. It  is  readily  seen,  therefore,  that  the  more 
concentrated  the  product,  the  less  will  be  the  actual  cost 
of  the  constituent  desired. 

Again,  fertilizers  may  be  bought  and  used  either  as 
"  incomplete,"  —  raw  materials,  —  or  as  "  complete,"  — 
manufactured  products  or  mixtures,  the  process  of  man- 
ufacture consisting  chiefly  in  mixing,  grinding,  and  pre- 
paring the  various  materials  described.  There  are  cer- 
tain advantages  and  disadvantages  in  both  methods  of 
buying.  The  advantages  in  the  purchase  and  use  of  raw 
materials  are :  — 

1.  A  better  knowledge  of  the  kind  and  quality  of 
plant-food  obtained ;  that  is,  these  products  as  a  rule  pos- 
sess characteristics  which  distinguish  them  from  others 
and  from  each  other,  and  they  are  more  liable  to  be 
uniform  in  composition  than  mixtures. 


ARTIFICIAL  MANURES  OR  FERTILIZERS.       103 

2.  The  using  of  one  or  more  of  the  constituents  as 
may  be  found  to  be  necessary,  thus  avoiding  the  expense 
of  purchasing  and  applying  those  not  required  for  the 
particular  crop  or  soil.  The  farmer  is  also  enabled  to 
adjust  the  forms  and  proportions  of  the  various  ingre- 
dients to  suit  what  he  has  found  to  answer  the  needs  of 
his  soil  or  crop. 

3.  A  saving  in  the  cost  of  plant-food,  since  in  their 
concentrated  form  the  expenses  of  handling,  shipment, 
bagging,  etc.,  are  reduced. 

The  chief  disadvantages  in  the  buying  and  use  of 
incomplete  fertilizers  are :  — 

1.  They  are  not  so  generally  distributed  among  dealers, 
and  thus  not  so  readily  obtained. 

2.  It  is  difficult  to  spread  evenly  and  thinly  products 
of  so  concentrated  a  character,  particularly  the  chemical 
salts,  which,  unless  great  care  is  used,  may  injure  by 
coming  in  immediate  contact  with  the  roots  of  plants. 

3.  The  mechanical  condition,  or  degree  of  fineness,  is 
less  perfect  than  in  the  manufactured  products. 

The  advantages  in  the  purchase  and  use  of  complete 
manures  are :  — 

1.  They  are  generally  distributed,  and  can  be  purchased 
in  such  amounts  and  at  such  times  as  are  convenient. 

2.  The  different  materials  may  be  well  proportioned, 
both  as  to  form  of  the  constituents  and  their  relative 
amount  for  the  various  crops. 

3.  The  products  are,  as  a  rule,  finely  ground  and  well 
prepared  for  immediate  use. 

The  chief  disadvantages  are  :  — 

1.  That  it  is  impossible  to  detect  in  a  mixture  whether 
the  materials  are  what  they  are  claimed  to  be. 


104         FIRST  PRINCIPLES  OF  AGRICULTURE. 

2.  That  without  a  true  knowledge  of  what  constitutes 
value,  many  are  led  to  purchase  on  the  ton  basis,  without 
regard  to  the  quantity  and  quality  of  the  plant-food  offered. 

Guarantee.  —  The  fact  that  consumers  are  unable  to 
determine  the  value  of  a  mixture  from  its  appearance, 
and  the  opportunity  thus  afforded  for  disguising  the 
presence  of  poor  forms  of  plant-food,  has  led  in  many 
states  to  the  enactment  of  laws  which  require  that  all 
manufacturers  shall  publish  the  actual  composition  of 
their  products,  and  also  state  the  kind  of  material  from 
which  the  constituents  have  been  derived;  or,  in  other 
words,  that  they  shall  guarantee  the  goods  to  contain 
certain  amounts  and  forms  of  the  three  plant-food  ele- 
ments, the  state  exercising  a  chemical  control  of  the 
products  sold. 

By  this  means,  spurious  articles  are  kept  from  the 
market,  and  good  manufacturers  and  farmers  are  pro- 
tected, though  it  is  left  still  to  the  intelligence  of  the 
farmer  to  determine  whether  there  is  a  proper  relation 
between  the  guarantee  and  selling  price. 

Interpretation  of  Guarantees.  —  The  statement  of  the 
guarantee  is  sometimes  confusing  to  purchasers,  as  differ- 
ent manufacturers  use  methods  which  seem  to  them  most 
desirable.    The  following  examples  illustrate  this  point :  — 

Guarantee    No.   1. 

Nitrogen  (equivalent  to  ammonia) 3-4% 

Available  Phosphoric  Acid  (equivalent  to  bone  phos.  of 

lime) 18-22% 

Potash  (equivalent  to  sulphate  of  potash) 10-12% 

Guarantee  No.   2. 

Nitrogen 2.50-  3.25% 

Available  Phosphoric  Acid 8.00-10.00% 

Potash  (actual) 5.50-  6.50% 


ARTIFICIAL  MANURES  OR  FERTILIZERS.       105 

The  guarantees  here  given  mean  practically  the  same 
in  both  cases.  In  No.  1  the  percentages  represent  the 
amounts  in  combination  with  other  elements ;  while  in 
No.  2  percentages  of  actual  constituents  are  stated,  viz., 
nitrogen,  phosphoric  acid,  and  potassium  oxide. 

In  order  to  convert  the  ammonia  into  its  equivalent 
of  nitrogen,  the  percentage  of  ammonia  may  be  multiplied 
by  eighty-two  per  cent,  or  divided  by  1.214 ;  since  ammo- 
nia is  eighty-two  per  cent  nitrogen,  and  since  one  part 
of  nitrogen  is  equal  to  1.214  parts  of  ammonia. 

Bone  phosphate  of  lime  is  forty-six  per  cent  actual 
phosphoric  acid;  hence  multiplying  the  bone  phosphate 
by  forty-six  per  cent  gives  the  per  cent  of  actual  phos- 
phoric acid.  Sulphate  of  potash  is  fifty-four  per  cent, 
and  muriate  of  potash  is  sixty-three  per  cent  actual  or 
potassium  oxide ;  hence,  to  convert  the  percentages  of 
these  forms  into  their  equivalents  of  actual,  they  are 
multiplied  by  the  factors  given. 

In  most  raw  materials  another  method  of  guaranteeing 
is  adopted,  because  in  these  the  guarantee  is  simply 
a  statement  of  their  purity.  For  instance,  nitrate  of 
soda  is  guaranteed  as  ninety-five  per  cent  pure  nitrate ; 
muriate  of  potash  is  guaranteed  eighty  per  cent  pure 
muriate,  etc.,  which  means  that  the  products  are  respec- 
tively ninety-five  and  eighty  per  cent  pure,  or  in  other 
words,  that  in  the  case  of  nitrate  five  per  cent  of  it  is 
something  other  than  nitrate  of  soda,  and  in  the  case  of 
the  muriate  twenty  per  cent  of  it  is  something  other 
than  muriate  of  potash. 

The  factors  necessary  to  use  in  the  conversion  of  the 
constituents    in    their    usual    form    of   combination    into 


106 


FIRST  PRINCIPLES  OF  AGRICULTURE. 


the   actual    are   shown    in   the    following    tabular    state- 
ment :  — 


TO  CONVEBT 

THB  GUABJLNTEE  OF                                                                                                    MULTIPLY  BT 

Ammonia                into  an  equivalent  of  nitrogen  .    .    . 

0.8235 

Nitrogen                    "     "            "           "    ammonia      .     . 

1.214 

Nitrate  of  soda          "     "            "           "    nitrogen  .    .    . 

16.47 

Bone  phosphate        "     "            "           "    phosphoric  acid 

0.458 

Phosphoric  acid        "     "            "           "    hone  phosphate 

2.183 

Muriate  of  potash     "     "            "           "    actual  potash    . 

0.632 

Actual  potash           "     "            "           "    muriate  of  potash 

1.583 

Sulphate  of  potash    "     "            "           "    actual  potash   . 

0.54 

Actual  potash           "     "            "           "    sulphate  of  potast 

i      1.85 

The  Unit  Basis  or  System.  —  What  is  known  as 
the  "unit  system"  of  stating  the  amount  of  plant-food 
contained  in  a  fertilizer  is  sometimes  employed;  the 
"  unit "  means  one  per  cent  on  the  basis  of  a  ton,  or 
twenty  pounds.  For  instance,  a  "  unit "  of  nitrogen 
means  twenty  pounds,  and  a  dried  blood  guaranteed  to 
contain  ten  units,  means  that  two  hundred  pounds  of 
nitrogen  is  contained  in  one  ton. 

This  system  is  largely  used  by  trade  journals  in  stat- 
ing quotations,  particularly  for  nitrogenous  and  phosphatic 
materials.  Purchasing  on  the  "  unit  basis "  is  the  true 
method,  and  hence  the  most  satisfactory  of  any  to  both 
the  producer  and  consumer,  and  should  be  adopted  in 
all  transactions.  It  means  that  the  consumer  secures 
what  he  pays  for,  and  the  producer  is  paid  for  exactly 
what  he  delivers. 

Purchasers  should  insist  that  any  material,  whether 
mixed  or  unmixed,  should  be  accompanied  by  a  guarantee. 

Commercial  Values.  —  The  commercial  value  of  raw 
materials  is  fixed  by  trade  conditions,  as  supply  and 
demand,   usefulness    in    the    arts    or    manufacture,    and 


ARTIFICIAL  MANURES   OR  FERTILIZERS.       107 

market  manipulations.  The  value  of  these  products  for 
fertilizing  purposes  depends  almost  entirely  upon  the 
constituents  contained;  hence  the  actual  cost  of  the  con- 
stituent is  readily  determined  when  the  factors,  price, 
and  amount  contained  in  a  given  quantity,  are  known. 
The  selling  price  of  nitrate  of  soda,  for  example,  is 
$48.00  per  ton;  and  as  a  ton  contains  on  the  average 
three  hundred  and  twenty  pounds  of  nitrogen,  the  cost 
or  commercial  value  of  nitrogen  is,  therefore,  fifteen 
cents  per  pound. 

In  many  States  a  system  of  valuation  for  mixed  ferti- 
lizers has  been  adopted,  which  furnishes  a  fair  method 
of  comparison  of  different  brands.  This  method  assumes 
that  at  points  of  supply  a  pound  of  nitrogen  in  the  form 
of  nitrate,  of  ammonia,  or  of  definite  organic  compounds, 
or  a  pound  of  available  phosphoric  acid,  or  of  potash  in 
the  form  of  muriate  or  sulphate,  is  practically  the  same 
to  all  manufacturers.  A  value  for  each  of  these  con- 
stituents derived  as  already  described,  when  applied  to 
the  constituents  in  the  mixture,  represents  the  cost  of 
the  elements  before  they  are  mixed  to  form  complete  fer- 
tilizers ;  and  hence  the  difference  between  the  valuation 
and  selling-price  of  a  brand  represents  the  charges,  includ- 
ing profit,  for  mixing,  bagging,  shipping,  and  selling  the 
goods. 

This  valuation  of  a  brand  is  commercial,  and  bears  no 
strict  relation  to  its  possible  agricultural  effect ;  it  simply 
states  that  so  many  pounds  of  the  constituents  as  are 
contained  in  a  ton  are  commercially  worth  the  value  given, 
at  point  of  production.  It  shows  what  a  given  lot  or 
brand   of   fertilizer  is   worth  as   a  commodity  of  trade ; 


108         FIRST  PRINCIPLES  OF  AGRICULTURE. 

what  it  costs;  and  a  comparison  of  the  valuation  and 
selling-price  of  a  number  in  connection  with  their  com- 
position indicates  which  is  the  best  for  the  money. 

Nitrogen  from  the  same  source  is  worth  no  more  in 
one  brand  than  in  another;  the  same  is  true  in  reference 
to  potash  and  available  phosphoric  acid. 

Analyses  of  Fertilizers.  —  The  chemical  analysis  of 
a  fertilizer  should  show,  as  far  as  possible,  both  the 
amount  and  form  of  either  or  all  of  the  three  con- 
stituents contained ;  viz.,  nitrogen,  phosphoric  acid,  and 
potash.  Such  a  complete  statement  gives  considerable 
information  as  to  the  source  and  quality  of  the  materials 
from  which  the  constituents  have  been  derived.  For  in- 
stance, if  the  analysis  shows  that  three  forms  of  nitro- 
gen are  present,  that  the  "total  available"  phosphoric 
acid  is  chiefly  soluble  in  water,  that  the  percentage  of 
insoluble  phosphoric  acid  is  low,  and  that  the  potash 
is  in  the  form  of  sulphate,  it  is  good  evidence  that  stan- 
ard  high-grade  goods  have  been  used. 

The  analysis  cannot,  however,  give  definite  and  positive 
information  as  to  the  source  of  organic  nitrogen,  whether 
from  the  best  form,  dried  blood,  or  from  the  poorest, 
leather.  Neither  is  it  possible  to  tell  absolutely  how 
much  of  the  insoluble  phosphoric  acid  has  been  derived 
from  organic  or  mineral  sources,  when  materials  from 
both  sources  have  been  used. 

Fertilizer  Formulas.  —  A  fertilizer  formula  indicates 
the  kind  and  quantity  of  raw  materials  to  be  used  to 
secure  certain  proportions  of  the  fertilizer  constituents. 
If  it  be  desired  to  secure  a  mixture  containing  four  per 
cent   nitrogen,   eight  and  eight-tenths   per  cent  available 


ARTIFICIAL  MANURES   OR  FERTILIZERS.      109 

phosphoric  acid,  and  ten  per  cent  of  actual  potash,  the 
following  materials  would  furnish  it,  assuming  an  aver- 
age analysis  for  them  :  — 

Formula  No.  1. 

Containing  Pounds  of 
Phosphoric 
Materials.  Amount.      Nitrogen.         ^cid.        Potash. 

Nitrate  of  Soda 500  lbs.  80 

Bone-black  Superphosphate   .    1,100  176 

Muriate  of  Potash      ....       400  200 

Total 2,000  80  176  200 

Guaranteed  Analysis 4%  8.8%        10% 

A  mixture   containing  two   and   one-half    per  cent  of 

nitrogen,  eight  per  cent  of  available  phosphoric  acid,  and 

two  per  cent  of  potash  may  be  made  from  the  following 

materials :  — 

Formula  No.  2. 

Containing  Pounds  of 

Phosphoric 
Materials.  Amount.      Nitrogen.         Acjd  Potash. 

Nitrate  of  Soda 150  lbs.  24 

Dissolved  Bone 1,300  26  160 

Muriate  of  Potash      ....         80  40 

Land  Plaster 470 

Total 2,000  50  160  40 

Guaranteed  Analysis 2.5%  8%  2% 

No.  1  is  a  high-grade  product,  both  in  respect  to 
quality  of  plant-food  and  concentration;  while  No.  2  is 
high-grade  only  in  respect  to  quality.  In  order  to  get 
the  plant-food  distributed  throughout  the  ton,  it  is  neces- 
sary to  add  what  is  called  a  "  make-weight "  or  diluent. 

High-grade  mixtures  cannot  be  made  from  low-grade 
materials.  Low-grade  mixtures  cannot  be  made  from 
high-grade  materials  without  adding  "  make-weight." 
The  advantages  of  high-grade  products  are  concentration 
and  high  quality  of  plant-food. 


110         FIRST  PRINCIPLES  OF  AGRICULTURE. 

Special  Formulas.  —  Frequently  a  large  number  of 
different  formulas  or  brands  are  placed  upon  the  market 
by  the  same  manufacturers.  The  claimed  purpose  in 
the  multiplication  of  brands  is  to  meet  the  various  de- 
mands of  the  consumer,  as  well  as  to  furnish  special 
preparations  which  shall  provide  a  large  proportion  of 
that  constituent  which  is  believed  to  be  of  special  ser- 
vice to  the  particular  crop. 

For  instance,  special  potato  manures  contain  a  much 
larger  proportion  of  potash  than  those  intended  for  gen- 
eral purposes.  Formula  No.  1  may  be  regarded  as  a 
special  potato  manure,  while  No.  2  may  be  regarded  as 
a  general  formula.  It  must  be  remembered  that  the 
amount  of  plant-food  applied  frequently  exercises  a 
greater  influence  than  mere  proportion  of  the  elements 
contained  in  it.  The  multiplication  of  brands  is  seldom 
of  advantage  to  the  consumer. 

The  Use  of  Fertilizers.  —  To  use  fertilizers  to  the 
greatest  advantage  it  is  requisite  that  a  great  many 
points  should  be  carefully  studied.  The  character  of  the 
manure  itself;  the  soil  and  previous  treatment,  both  in 
reference  to  manuring  and  cropping  ;  the  climate  ;  the 
character  of  the  crop  to  be  grown,  and  the  object  of 
its  growth,  —  are,  perhaps,  the  chief  factors  to  be  taken 
into  consideration. 

It  has  already  been  pointed  out  that  the  manurial 
constituents  exist  in  various  degrees  of  availability,  from 
complete  solubility  in  water  to  insolubility  except  in 
strong  acids;  the  character  of  both  the  soluble  and  the 
insoluble  determines  its  usefulness  to  the  plant.  A 
correct  knowledge   of  the   action  of  these   is,  therefore, 


ARTIFICIAL  MANURES  OR  FERTILIZERS.        Ill 

of  the  first  importance  in  order  to  economically  use 
them. 

Nitrogenous  Manures.  —  In  reference  to  nitrogenous 
manures,  it  may  be  stated,  that,  because  nitrogen  in  the 
form  of  a  nitrate  is  immediately  available,  and  because 
it  is  freely  movable,  and  is  not  retained  by  the  soil, 
nitrate  should  not  be  applied  in  any  considerable  amount 
before  the  plant  is  growing  and  ready  to  use  it.  While 
in  the  case  of  nitrogen  in  the  form  of  ammonia,  though 
it  is  completely  soluble  in  water,  it  is  absorbed  by  the 
soil,  and  requires  an  appreciable  time  to  change  into 
the  form  of  a  nitrate,  and  may,  therefore,  be  applied 
without  risk  of  loss  a  short  time  before  it  is  likely  to 
be  used. 

On  the  other  hand,  nitrogen  in  organic  forms  shows 
a  wide  range  of  availability,  the  readily  soluble  blood 
ranking  with  the  nitrate  and  ammonia;  while  leather, 
wool  waste,  shoddy,  and  like  products,  which  decay  very 
slowly,  should  be  applied  a  considerable  time  before  the 
nitrogen  in  them  is  required. 

Phosphatic  Manures.  —  In  the  case  of  phosphatic 
manures,  the  soluble  forms,  or  superphosphates,  should 
be  applied  but  a  short  time  before  the  plant  requires 
the  food,  since  their  tendency  in  the  soil  is  to  revert  to 
their  original  and  insoluble  forms.  Coarse  bone,  ground 
mineral  phosphates,  and  products  of  like  character,  decay 
slowly,  and  should  be  applied  a  long  time  before  they 
are  likely  to  be  used. 

Potash  Manures.  —  The  potash  manures  from  the 
Stassfurt  mines  are  readily  soluble ;  they  should,  how- 
ever, be  applied  some  time  before  they  are  required,  in 


112         FIBST  PRINCIPLES   OF  AGRICULTURE. 

order  to  secure  their  complete  distribution  in  the  soil. 
On  soils  of  a  heavy  character  a  fall  application  is  recom- 
mended. 

In  order  to  attain  the  best  results  from  mixed  fertili- 
zers, great  care  should  be  given  to  the  proper  adjustment 
of  the  various  kinds  and  forms  of  the  materials  used. 

Kind  of  Soils.  —  Crops  grown  upon  soils  poor  in 
decaying  vegetable  matter  are,  as  a  rule,  benefited  by 
nitrogen  manuring,  while  those  upon  soils  rich  in  this 
substance  are  more  benefited  by  phosphates  and  potash. 
Upon  heavy  soils  phosphates  are  likely  to  be  more 
beneficial  than  nitrogen,  while  the  reverse  is  the  case 
on  light,  dry  soils.  All  sandy  soils  are,  as  a  rule,  defi- 
cient in  potash,  while  clayey  soils  contain  this  element 
in  larger  quantities. 

Different  Methods  of  Growth.  —  The  difference  in 
crops  in  reference  to  their  capacity  for  acquiring  food 
must  also  guide  in  the  application  of  manures.  Crops 
that  have  deep  roots,  and  grow  throughout  a  long  sea- 
son, are  able  to  acquire  their  necessary  food  where  those 
of  shallow  roots  and  short  seasons  of  growth  would 
suffer  hunger. 

Crops  of  the  same  class,  too,  resemble  each  other  to 
some  extent  in  their  capacity  for  acquiring  food.  The 
grasses,  for  example,  do  not  possess  a  strong  power  of 
assimilating  nitrogen ;  root  crops  possess  a  small  capacity 
for  acquiring  and  utilizing  phosphoric  acid;  while  legu- 
minous plants  are  unable  to  readily  assimilate  potash; 
hence  these  crops  are,  in  the  order  given,  most  benefited 
by  nitrogen,  phosphoric  acid,  and  potash. 


THE  ROTATION  OF  CROPS.  113 


CHAPTER   X. 
The  Rotation  of  Crops. 

The  aim  of  the  farmer,  as  well  as  those  engaged  in 
other  industrial  pursuits,  is  to  derive  the  greatest  pos- 
sible return  both  for  his  labor  and  money  invested.  The 
selection  of  definite  lines  of  farming,  or  the  growth  of 
crops  profitable  for  his  conditions,  becomes,  then,  of 
great  importance. 

The  Demand  for  Special  Crops.  —  In  the  earlier 
history  of  the  country,  selection  was  practically  limited 
to  the  staple  crops  of  grain  and  hay.  As  the  country 
developed  and  increased  in  wealth,  larger  demands  were 
made  for  fruits,  vegetables,  and  such  special  products 
as  were  in  former  times  regarded  as  luxuries,  and  the 
production  of  which  was  confined  to  the  areas  of  gardens 
and  yards. 

At  the  present  time,  therefore,  particularly  in  the 
Eastern  States,  general  farming  is  the  exception  rather 
than  the  rule,  and  special  farming  is  more  profitable. 
The  raising  of  hay,  grain,  vegetables,  and  fruits,  and 
dairy  products,  now  forms  distinct  lines.  The  adoption  of 
either  or  any  of  these  depends  upon  a  variety  of  cir- 
cumstances, though  chiefly  upon  the  following :  the  condi- 
tions of  soil  and  climatic  influences ;  the  location  of  the 
farm  in  respect  to  markets;  and  the  probable  profit. 


114         FIRST  PRINCIPLES   OF  AGRICULTURE. 

In  any  or  all  of  these  lines,  however,  certain  groups 
of  crops  may  be  more  profitable  than  others.  This  is 
because  it  has  been  found  to  be  more  desirable  in  the 
long  run  to  have  a  variety,  one  following  the  other  in 
a  definite  rotation.  In  the  cotton  and  sugar  producing 
States  of  the  South,  and  the  wheat  growing  States  of  the 
Northwest,  rotation  is  least  practised,  while  in  the  East- 
ern States  and  the  Central  West,  rotations  are  the  rule. 

The  practice  of  growing  different  crops  in  rotation, 
while  largely  a  matter  of  conditions,  does  possess  cer- 
tain advantages,  —  based  upon  scientific  principles,  as 
having  reference  to  the  character  of  growth  and  feeding 
capacities  of  plants,  and  upon  business  principles,  as  hav- 
ing reference  to  a  better  division  of  labor  and  a  more 
certain  income. 

The  Advantages  of  Rotations.  —  The  advantages  of 
rotations  may  be  stated  as  follows :  — 

1.  The  feeding  capacities  of  plants  differ,  certain  of 
them  requiring  more  of  one  particular  element  than  of 
another ;  certain  are  surface  feeders,  and  others  send 
their  roots  deep  into  the  subsoil.  The  growth  of  a 
variety  of  plants  with  different  capacities,  therefore, 
prolongs  the  period  of  profitable  culture,  or  retards  soil 
exhaustion. 

2.  The  growing  of  but  one  crop  leaves  the  soil  bare 
at  certain  seasons  of  the  year,  while  a  variety  permits 
of  a  continuous  growth  and  covering  of  the  soil.  Soils 
suffer  loss  when  lying  idle;  they  are  improved  by  the 
growth  of  crops. 

3.  The  continuous  growth  of  one  crop  renders  it  more 
liable  to  insect  attack,  and  to  the  development  of  dis- 


THE  ROTATION  OF  CROPS.  115 

eases  that  cause  rot  and  blight.  Crops  lose  vigor  by 
being  grown  year  after  year,  and  thus  are  less  able  to 
withstand  these  attacks ;  besides,  a  change  of  crops  de- 
prives the  pests  of  their  particular  kind  of  food,  causing 
them  to  disappear  or  perish. 

4.  Certain  crops  derive  their  nitrogen,  phosphoric  acid, 
and  potash  entirely  from  the  soil ;  the  cereals  grown 
for  their  grain,  which  is  usually  sold,  belong  to  this 
class.  Certain  others,  the  clovers,  peas,  and  beans,  de- 
rive their  nitrogen  from  the  atmosphere  ;  their  removal 
does  not  decrease  the  store  of  nitrogen  in  the  soil.  A 
rotation  of  crops,  including  the  latter,  therefore,  lessens 
the  necessity  for  nitrogenous  manuring. 

5.  A  rotation  of  crops  distributes  labor  throughout 
the  season,  thus  giving  continuous  work  for  men  and 
horses.  In  farming  districts  it  is  difficult  to  procure 
labor  for  short  periods,  while  horses  have  to  be  kept 
throughout  the  year. 

6.  A  variety  of  crops  marketed  at  different  periods, 
permits  a  steady  and  regular  income  to  the  farmer,  which 
enables  him  to  do  business  on  a  smaller  capital ;  wages 
can  be  paid  when  due,  and  his  supplies  of  seeds,  fer- 
tilizers, implements,  aud  tools  can  be  bought  in  the 
lowest  market  for  cash. 

It  has  already  been  stated  that  the  adoption  of  what 
are  now  "systems  of  crop  rotation"  was  largely  a  matter 
of  growth,  due  to  circumstances,  and  was  not  in  the  be- 
ginning based  upon  scientific  principles.  Science,  how- 
ever, furnishes  the  reasons  why  rotations  are  useful,  and 
why  certain  rotations  are  more  useful  than  others. 

The   Need  of  Rotations.  —  The  need  of  rotation  as 


116         FIRST  PRINCIPLES  OF  AGRICULTURE. 

a  means  of  maintaining  fertility  was  apparent  in  early 
times,  when  the  manures  were  confined  to  the  natural 
wastes  of  the  farm,  and  when  the  growth  of  livestock 
and  production  of  dairy  products  were  industries  of  but 
little  importance.  It  is  less  apparent  now,  when  the 
materials  furnishing  available  plant-food  elements  or  arti- 
ficial manures  are  so  abundant  and  cheap.  Formerly, 
the  proportion  of  active  soil  constituents  was  almost  en- 
tirely dependent  upon  the  natural  forces  that  were 
brought  to  bear  upon  the  dormant  constituents  to  con- 
vert them  into  activity;  under  the  conditions  that  exist 
now,  it  is  frequently  more  economical  to  purchase  the 
active  constituents  and  apply  them  to  the  soil;  in  other 
words,  to  supplement  natural  forces  by  artificial. 

Bare  Fallow.  —  In  the  older  systems  of  rotation,  it 
was  customary  to  allow  the  land  to  lie  bare,  or  "fallow," 
once  in  two  or  three  years,  in  order  that  the  natural 
agencies,  sun,  air,  and  water,  might  have  free  access,  cause 
a  more  rapid  decay  of  the  soil  particles,  and  make  it  more 
fertile,  a  practice  extending  the  period  of  profitable  crop- 
ping without  manure.  Sometimes  the  fields  were  left 
entirely  to  themselves,  while  in  others  they  were  fre- 
quently plowed  or  stirred  in  order  to  hasten  the  decay. 

Fallow  Crops.  —  Following  this  method  came  "crop- 
fallowing,"  which  is  still  practised;  that  is,  instead  of 
allowing  the  land  to  remain  idle  after  a  grain  crop  has 
been  removed,  a  cultivable  crop,  as  turnips  or  roots,  is 
planted,  or  a  catch  crop,  as  clover,  is  seeded,  the  culti- 
vation of  the  one  assisting  in  the  decay  of  vegetable  and 
mineral  matter,  thus  improving  for  a  subsequent  grain 
crop ;  while  the  other,  because  of  its  different  method  of 


THE  ROTATION   OF  CROPS.  117 

growth  and  greater  power  of  acquiring  food,  assists  in 
renovating  and  improving  the  soil. 

Rotations  to  be  Adopted.  —  The  rules  which  govern 
the  adoption  of  systems  of  rotation,  under  the  conditions 
that  now  exist,  are  general  and  flexible,  rather  than  spe- 
cific and  fixed.  To  grow  the  crops  that  pay  the  greatest 
profit  per  acre  should  be  the  aim,  and  rotations  should 
be  modified  in  such  a  way  that  the  least  profitable  crops 
should  contribute  as  much  as  possible  to  the  development 
of  the  most  profitable.  The  character  of  soil,  climate, 
availability  of  farm-labor,  location,  markets,  —  all  have  an 
influence  in  determining  what  the  most  profitable  crop 
may  be. 

For  instance,  hay  may  be  high  in  price  in  a  given 
locality:  the  soil  is  dry  and  sandy;  hay  burns  on  the 
ground ;  the  yield  is  light,  and  it  does  not  pay  to  raise 
it,  even  at  high  prices.  In  another  locality  sweet  potatoes 
may  bring  three  dollars  per  barrel :  the  land  is  a  clay, 
cold  and  heavy ;  it  is  suitable  for  hay,  not  sweet  potatoes. 
Reverse  the  order,  and  both  may  be  profitable  crops.  On 
the  light,  sandy  land  the  rotations  adopted  should  be  such 
as  contribute  to  the  best  development  of  the  sweet  pota- 
toes, and  on  the  heavy  clay,  such  as  aid  in  preparing 
the  soil  to  produce  the  largest  hay  crop. 

The  climate,  in  the  same  manner,  places  a  limit  upon 
the  production  of  certain  crops.  A  short,  cool  season  is 
not  favorable  for  the  corn  crop  ;  it  will  not  mature :  hence 
corn  should  not  be  included  in  a  rotation  under  such 
conditions.  In  many  cases  farms  do  not  pay  because 
their  owners  have  not  studied  their  conditions  in  refer- 
ence to  paying  crops,  and  adapted  themselves  to  them. 


118         FIRST  PRINCIPLES  OF  AGRICULTURE. 

Rotation  Courses.  —  The  number  of  years  intervening 
between  the  growth  of  crops  in  regular  order  is  termed 
a  "course."  A  rotation  course  may  range  from  the  sim- 
ple two-year  to  the  more  complex  six  or  eight  year 
course,  though  the  four-year  course  is  generally  adopted. 
The  poorer  the  land  the  shorter  the  course ;  and  the 
reverse,  the  better  the  land  the  longer  the  course,  —  are 
principles  now  well  established. 

Taking  the  number  of  crops  and  periods  of  rotation 
possible,  it  is  evident  that  the  number  of  possible  courses 
is  too  large  to  admit  of  definite  description  or  comment. 
A  few  examples  only  are  given  and  discussed,  in  order  to 
more  clearly  illustrate  the  principles  already  pointed  out. 

Examples  of  Rotation  Courses.  —  These  are  adapted 
to  what  is  termed  "  arable  farming,"  where  the  live  stock 
is  only  sufficient  to  provide  labor  and  the  necessities  of 
the  family. 


First  Year. 

Second  Teak. 

Thibd  Year. 

Fourth  Year. 

1.   Corn. 

Oats. 

Wheat. 

Clover. 

2.  Corn. 

Wheat. 

Clover. 

3.  Corn. 

Potatoes. 

Wheat. 

Clover. 

4.   Corn. 

Potatoes. 

Clover. 

5.  Potatoes. 

"Wheat. 

Clover. 

No.  1  is  defective  for  two  reasons :  first,  because  uncul- 
tivated crops  similar  in  character  and  capacity  of  obtain- 
ing plant-food  succeed  each  other;  and  second,  because 
the  oats  preceding  the  wheat  prevents  a  proper  cultivation 
of  the  soil  and  preparation  of  the  seed-bed  for  wheat. 
This  rotation  is  widely  used,  mainly  because  it  is  eco- 
nomical of  labor.  Until  very  recently  the  custom  was 
to  plant  the  corn  on  clover-sod,  follow  with  oats  without 
manure,  and  then  lime  and  manure  for  wheat. 


THE  ROTATION  OF  CROPS.  119 

This  custom  is  now  rapidly  changing,  and  for  the  bet- 
ter; viz.,  to  manure  the  corn,  and  to  provide  artificial 
fertilizers  for  the  oats  and  wheat.  The  latter  method  is 
more  reasonable,  since  it  permits  of  the  removal  of  the 
manure  from  the  yard  to  the  field  during  the  leisure  of 
winter  and  spring,  and  the  increased  profit  from  its  use 
is  received  in  the  year  of  its  application.  It  is  more 
economical  of  labor  and  capital.  In  all  the  rotations 
where  clover  follows  wheat,  it  is  usually  seeded  in  the 
growing  wheat  in  early  spring. 

No.  2  is  particularly  adapted  to  light  lands,  as  it 
admits  of  a  more  frequent  repetition  of  the  renovating 
clover  crop.  It  is  objectionable,  however,  where  the 
seasons  are  short,  since  to  wait  for  seeding  the  wheat 
until  after  the  corn  is  fit  to  harvest  does  not  allow  it  to 
make  sufficient  top  to  withstand  the  winter  well ;  besides, 
the  early  removal  of  the  corn  is  very  laborious  and  expen- 
sive. 

No.  3  is  a  typical  rotation,  since  the  crops  of  cereals 
are  separated  by  a  root  or  clover  crop.  This  rotation 
corresponds  to  the  Norfolk  system,  so  widely  adopted  in 
England;  viz.,  turnips,  barley,  clover,  wheat.  In  many 
sections  of  this  country  the  potatoes  are  the  best  paying 
crop.  The  corn  is  planted  on  a  clover-sod,  and  yard- 
manure  liberally  applied ;  the  cotn,  being  a  gross  feeder, 
utilizes  sufficient  food  for  its  normal  growth  from  the 
partial  decay  of  the  manure,  roots,  and  stubble,  and  the  cul- 
tivation of  the  corn  puts  the  land  in  excellent  tilth  for 
the  potatoes.  Artificial  manures  are  mainly  used  for  this 
crop,  frequently  in  large  amounts,  the  residues  from  which 
guarantee  maximum  crops  of  both  wheat  and  clover. 


120         FIB  ST  PRINCIPLES   OF  AGRICULTURE. 

In  No.  4  wheat  is  dispensed  with,  and  in  No.  5,  corn. 
Both  are  excellent  where  potatoes  or  root  crops  can  be 
grown  to  advantage;  and,  if  the  land  is  naturally  rich, 
the  frequent  tillage,  and  use  of  clover  crops,  provide  an 
abundance  of  available  food  for  maximum  crops,  provided 
the  second  crop  of  clover  is  not  removed. 

No.  5  may  be  reduced  to  a  two-year  rotation  by  plow- 
ing the  clover  in  spring  before  removing  any  crop.  In 
these  rotations  barley  may  be  substituted  for  oats,  rye 
for  wheat,  and  sweet  potatoes  or  tomatoes  for  potatoes, 
without  interfering  with  the  usefulness  of  the  rotation. 

Kotations  on  heavy  land,  where  hay  is  an  important 
crop,  differ  mainly  from  those  already  mentioned  in  hav- 
ing a  larger  number  of  crops.  Timothy  is  seeded  with 
the  wheat  in  addition  to  clover  in  the  spring.  The  first 
year  after  wheat,  a  mixed  hay  crop  is  gathered,  which 
becomes  almost  pure  timothy  in  the  next  season,  and 
purer  still  in  that  following;  hay  is  cut  two  or  three 
years  or  longer,  as  the  strength  and  character  of  soil  per- 
mit. Cropping  in  this  way  is,  however,  exhaustive,  and 
requires  careful  manuring.  These  rotations  have  refer- 
ence to  what  is  termed  "extensive  practice,"  and  do  not 
provide  for  the  manuring  of  each  crop,  though  it  does 
not  follow  that  it  cannot  be  made  "intensive." 

Eotations  in  Market-gardening  and  on  Dairy 
Farms.  —  In  market-gardening  and  dairy-farming,  ma- 
nures are  relied  on  to  a  greater  extent,  and  less  attention 
is  given  to  strict  rotations.  These  lines  of  farming  are 
more  on  the  "  intensive  plan,"  the  areas  are  limited,  the 
cropping  constant,  the  manuring  liberal,  and  the  crops  as 
large  as  conditions  of  climate  and  season  will  permit. 


THE  ROTATION  OF  CROPS.  121 

The  market-gardener,  as  soon  as  one  crop  is  removed, 
plants  another,  keeping  the  land  constantly  occupied.  He 
does  not  depend  upon  natural  fertility,  but  forces  growth 
by  the  abundant  supply  of  natural  and  artificial  manures. 
The  rotation  practised  is  governed  by  the  conditions 
which  control  the  kind  of  crops  he  can  grow  to  advan- 
tage, rather  than  by  considerations  of  soil  fertility. 

In  dairying,  the  object  is  to  provide  a  continuous  sup- 
ply of  food  ;  hence  the  rotation  adopted  is  the  one  which 
will  best  meet  this  requirement. 


122        FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTEK  XI. 

The  Selection  of  Seed ;  Farm  Crops  and  Their  Classification ; 
Cereals ;  Grasses ;  Pastures  ;  Eoots ;  Tubers ;  and  Market-gar- 
den Crops. 

Selection  of  Seed.  —  The  kind  of  seed  used  exercises 
an  important  influence  upon  the  yield  and  quality  of  the 
crop,  and  also  saves  the  farmer  losses  due  to  a  poor  stand. 
The  larger  the  proportion  of  living  seed  true  to  kind,  the 
greater  the  chances  of  a  perfect  stand  and  a  normal  and 
healthy  growth  of  crop.  In  the  case  of  the  larger  seed, 
as  the  cereals,  it  is  not  so  difficult  to  determine  quality 
as  in  the  case  of  certain  grasses  and  garden  seeds;  here 
a  careful  examination  and  testing  are  required. 

Good  Seed.  —  The  term  "  good  seed  "  implies  that  any 
given  lot  should  show  a  large  proportion  of  mature  seed, 
true  to  kind  and  variety,  and  a  small  proportion  of  impu- 
rities and  adulterants.  "  Mature  seed "  are  those  that 
have  fully  ripened,  and  are  capable  of  performing  well 
all  of  the  functions  of  germination ;  that  is,  they  are  capa- 
ble of  using  the  food  stored  up  in  them,  and  developing 
vigorous  and  healthy  young  plants.  "  Immature  seed  " 
are  those  that  have  not  fully  developed  or  ripened,  and 
can  only  partially  perform  the  functions  of  germination. 
The  young  plant  lacks  strength  and  vigor. 

Impurities.  —  Impurities   include   all  foreign    matter, 


SELECTION  OF  SEED  ;    FARM  CROPS.  123 

both  injurious  and  harmless,  that  may  be  present  in  the 
seed  purchased,  as  seeds  not  genuine,  dirt,  dust,  weed-seed, 
chaff,  and  diseased  seed.  The  presence  of  weed-seed  per- 
haps results  on  the  whole  in  the  greatest  loss  and  annoy- 
ance, —  in  the  first  place,  the  loss  of  return  from  land 
taken  up  by  the  weeds,  hence  a  reduction  in  crop;  and 
second,  the  difficulty  and  expense  of  eradicating  the  weeds 
when  well  established. 

Adulteration.  —  Adulteration  of  seed  includes,  first, 
the  substitution  of  cheaper  seed  for  the  more  valuable, 
which  is  frequently  practised  in  the  case  of  mixed  seeds 
that  resemble  each  other,  and  second,  the  removal  of  the 
evidences  of  age  or  disease.  Seed  that  are  musty  or  dark 
are  sometimes  sweetened  and  brightened  by  bleaching 
with  fumes  of  sulphur. 

Quality  of  Seed.  —  The  quality  of  genuine  seed  is 
influenced  by  age,  size,  weight,  and  smell.  Old  seed  are 
less  likely  to  germinate  than  new;  the  loss  of  vitality 
is  gradual,  though  more  rapid  in  unripe  than  in  well- 
ripened  seed ;  the  larger  and  heavier  seeds  also  die  more 
slowly  than  the  smaller  and  lighter  ones. 

The  seed  of  the  cereals  and  grasses  lose  germinating 
power  and  vigor  rapidly  after  the  first  year ;  though  alive, 
they  germinate  and  grow  slowly,  thus  causing  a  loss  of 
time  at  the  beginning  of  the  season,  and  the  slow  growth  of 
the  plant  at  its  most  tender  stage  increases  the  tendency 
to  disease  and  insect  attack. 

Seed  may  also  be  killed  by  a  too  rapid  or  too  complete 
removal  of  water  from  them  ;  hence  artificial  drying,  if 
improperly  conducted,  that  is,  if  too  great  heat  is  used, 
may  result  in  the  death  of  the  germ. 


124         FIRST  PRINCIPLES  OF  AGRICULTURE. 

If  a  crop  from  which  seed  is  to  be  gathered  is  stored 
before  thoroughly  dry  in  a  damp  place,  it  is  liable  to  be- 
come hot,  which  destroys  in  a  great  degree  the  germinating 
power  of  the  seed.  Crops  from  which  seed  is  to  be  se- 
cured should  be  carefully  dried,  and  stored  in  a  dry  place. 

Change  of  Seed.  —  The  improved  varieties  of  farm 
crops  of  the  same  kind  have  been  developed  by  the  careful 
selection  of  the  best  seed  of  these  crops  grown  under  the 
most  favorable  conditions  of  climate,  season,  soil,  and  man- 
agement. The  natural  tendency  of  the  plant,  even  under 
favorable  conditions,  is  to  go  back  to  its  original  and  in- 
ferior state ;  hence,  when  the  conditions  of  growth  are 
unfavorable,  this  tendency  is  increased.  A  change  of  cli- 
mate, a  season  too  cool  or  too  hot,  too  dry  or  too  wet,  a 
poor  soil,  lack  of  care  in  cultivation,  —  all  aid  in  increas- 
ing this  backward  tendency;  the  conditions  are  not  per- 
fect, and  the  seed,  as  it  is  commonly  expressed,  "runs 
out,"  and  a  change  becomes  necessary. 

In  making  the  change,  seed  should  never  be  taken 
from  good  to  poorer  conditions,  but  rather  from  poor  to 
good;  that  is,  the  seed  from  crops  grown  under  good 
conditions  of  climate,  soil,  and  management  will  not  re- 
tain their  character  so  well  when  grown  under  condi- 
tions poorer  in  these  respects,  while  the  seed  from  crops 
which  nourish  well  under  poor  conditions  are  likely  to 
not  only  retain  their  character,  but  improve  when  changed 
to  good  conditions. 

It  is  also  true  that  seed  from  crops  that  do  well  in  rig- 
orous climates  are  more  likely  to  improve  when  brought 
under  more  favorable  conditions  in  this  respect  than 
when  those  that  do  well   in  a  warm  climate  are  brought 


SELECTION  OF  SEED;    FARM  CROPS.         125 

into  a  colder  climate.  In  other  words,  in  changing 
seed,  particularly  of  the  cereals,  they  should  be  secured 
from  the  North  rather  than  from  the  South.  These  are, 
however,  general  suggestions,  to  be  used  as  guides  rather 
than  as  specific  and  definite  rules. 

Seed-Testing.  —  The  number  of  pure  seed  and  the 
germinating  power  are  the  two  factors  which  determine 
the  number  of  plants  that  may  be  obtained  from  a  given 
quantity,  rather  than  the  bushels  of  seed  sown.  Seed- 
testing  includes,  therefore,  a  test  of  purity  and  of  ger- 
minating power. 

Purity.  —  The  purity  may  be  tested  by  taking  a  def- 
inite weight  to  represent  the  product,  and  separating  the 
foreign  matter,  either  by  hand  or  by  means  of  a  sieve, 
then  weighing  the  remainder  of  pure  seed.     For  example : 

Total  weight  taken     .      100  grains  or  grams. 
Weight  of  pure  seed  .       95      "  " 

Weight  of  impurities .         5      "  " 

The  amount  of  pure  seed  is,  therefore,  95  per  cent, 
while  the  amount  of  impurities  is  5  per  cent. 

It  is  better  in  stating  the  impurity,  consisting  of  for- 
eign seeds,  weed-seeds,  etc.,  to  use  the  number  of  seed  in- 
stead of  their  weight,  as  it  gives  a  better  idea  of  the 
possible  damage  from  its  seeding. 

Germinating  Power.  —  In  testing  the  germinating 
power,  only  the  seed  true  to  kind  are  tested;  hence,  a 
high  germinating  power  is  not  in  itself  sufficient  evi- 
dence of  quality.  It  must  be  accompanied  by  a  statement 
as  to  purity;  for  instance,  if  the  germinating  power  is 
ninety  per  cent,  and  the  purity  only  twenty-five  per  cent, 


126         FIRST  PRINCIPLES  OF  AGRICULTURE. 

the  quality  of  the  seed  is  low,  since  out  of  one  hundred 
pounds  only  twenty-two  and  five-tenths  pounds  consist  of 
pure  germinating  seed.  Good  seed  shows  a  high  percen- 
tage of  both  purity  and  germinating   power. 

To  test  germination,  two  lots  of  at  least  one  hundred 
seeds  each  are  selected,  and  placed  under  conditions  favor- 
able for  germination ;  viz.,  moisture,  warmth,  and  air.  A 
box  containing  a  thin  layer  of  fine  soil,  kept  well  moist- 
ened, and  in  a  warm  place,  answers  the  purpose  nicely. 
The  chief  precautions  to  observe  are  to  keep  the  material 
moist  and  the  temperature  between  80°  to  90°  F. 

Plants  are  classified  by  botanists  into  families  or  nat- 
ural orders;  by  farmers  into  groups,  made  distinct  by 
methods  of  rotation  or  other  local  causes. 

Botanical  Classification.  —  This  is  a  useful  guide 
to  the  farmer  in  indicating  habits  of  growth,  as  well  as 
methods  of  manuring  and  management,  since  plants  of 
common  origin  or  ancestry,  though  differing  in  outward 
form,  are  quite  likely  to  be  benefited  by  the  same  kinds 
of  food,  to  be  subject  to  the  same  class  of  diseases,  and 
to  be  attacked  by  the  same  kind  of  insects.  The  differ- 
ent families  also  include  a  number  of  plants  not  useful 
as  farm  or  garden  crops,  though  all  possess  certain  char- 
acteristics in  common. 

The  Grass  Family.  —  The  first  natural  order  in  point 
of  usefulness  is  the  grass  family.  This  includes  the  ce- 
reals, wheat,  rye,  oats,  barley,  corn,  and  rice,  valuable 
chiefly  for  their  seed  or  grain ;  and  the  grasses,  valuable  as 
hay  and  pastures,  of  which  timothy,  orchard  grass,  rye 
grass,  blue  grass,  and  red-top,  are  prominent  examples. 

The   Family  which   includes   the   Potato,   valuable 


SELECTION  OF  SEED;    FABM  CROPS.  127 

for  starchy  food,  the  tomato  and  egg-plant,  useful  for 
their  fruit,  and  tobacco,  a  plant  of  great  commercial  value, 
is  also  very  important.  Many  plants  of  this  family  are 
poisonous,  of  which  "  henbane  "  and  deadly  "  nightshade  " 
are  examples  ;  in  fact,  the  fruit  and  vine  of  the  potato 
contain  poisonous  principles.  In  point  of  food  value  the 
potato  stands  next  to  the  cereals. 

The  Sweet  Potato  belongs  to  the  morning-glory  fam- 
ily, and  is  the  chief  food-plant  belonging  to  this  order. 

The  Legume  or  Clover  Family  includes  a  very  large 
number  of  plants,  as  herbs,  shrubs,  and  trees.  A  distin- 
guishing feature  of  this  order  is  the  formation  of  seed 
in  a  pod  or  legume.  Those  in  which  the  seed  or  grain 
is  used  as  food,  as  peas,  beans,  and  lentils,  are  called 
"  pulse ; "  hence  this  name  has  been  extended  to  all  the 
food  plants  of  this  order.  Leguminous  crops  are  called 
"pulse  crops." 

The  other  plants  of  this  family,  useful  as  hay,  green 
forage,  or  pasture,  are  the  various  clovers,  white  or  Dutch 
clover,  red  clover,  alsike  or  Swedish  clover,  and  crimson 
or  scarlet  clover,  also  lucerne  or  alfalfa,  vetches,  lupins, 
serradella,  and  sanfoin.  These  plants  are  among  the 
most  valuable  of  our  forage  crops.  They  have  strong 
foraging  powers  for  mineral  constituents,  and  are  also 
able  to  secure  the  nitrogen  necessary  for  their  growth 
from  the  air ;  thus  they  enrich,  rather  than  impoverish, 
the  soil  of  the  most  important  element, —  nitrogen. 

The  Turnip  Family  includes  among  the  edible  plants, 
turnips,  the  various  varieties  of  cabbage,  as  cauliflower, 
kale,  kohlrabi,  mustard,  radish,  horseradish,  and  watercress, 
and  the  forage  plants,  swedes  and  rape.     This  order  also 


128         FIRST  PRINCIPLES  OF  AGRICULTURE. 

includes  a  large  number  of  weeds,  of  which  shepherd's- 
purse,  charlock,  and  wild  radish  are  prominent  examples. 

The  Beet  Family  includes  the  food-plants,  garden- 
beets,  sugar-beets,  and  spinach,  and  the  mangel-wurzel, 
an  important  fodder  plant.  The  sugar-beet  is  of  great 
importance  in  Germany  and  France  as  a  commercial 
source  of  sugar,  while  the  mangel-wurzel  is  extensively 
raised  as  a  fodder  crop. 

The  Melon  Family  is  extensive,  though  it  does  not 
include  any  strictly  farm  crops.  Cucumbers,  melons, 
pumpkins,  and  gourds  are  prominent  examples  of  this 
order :  "  cucurbs "  is  a  term  also  applied  to  this  group 
of  plants. 

The  Carrot  Family  includes  carrots,  parsnips,  parsley, 
and  celery,  while  lettuce  belongs  to  the  dandelion  family, 
and  the  onion  and  asparagus  to  the  lily  family. 

The  Hose  Family  is  an  important  natural  order.  It 
includes  herbs,  shrubs,  and  trees,  to  which  belong  the 
most  important  of  our  fruits.  One  type  is  represented 
by  the  plum,  peach,  cherry,  apricot,  nectarine,  and  almond ; 
another,  by  the  raspberry,  blackberry,  and  dewberry;  and 
still  another,  by  the  apple  and  pear.  The  bush-fruits, 
gooseberry  and  currant,  are  both  members  of  another 
distinct  natural  order. 

Agricultural  Classification.  —  While  the  grouping  of 
plants  by  the  method  described  is  useful,  an  agricultural 
classification,  which  groups  the  various  crops  according  to 
their  similarity  of  growth,  management,  and  treatment,  is 
also  convenient  to  the  farmer;  and  the  following  method 
permits  of  a  logical  discussion  of  the  principles  involved 
in  their  growth:  — 


SELECTION  OF  SEED;    FARM  CROPS.  129 

1.  Cereal  crops:    Wheat,  rye,  oats,  barley,  and  corn. 

2.  Forage  crops:   Grasses  and  clovers  for  forage  hay  and  pasture. 

3.  Root  crops:       Turnips,  swedes,  carrots,  and  mangels. 

4.  Tuber  crops:     White  potato  and  sweet  potato. 

5.  Miscellaneous  crops:   Market-garden  and  fruit  crops. 

Cereal  Crops.  —  The  chief  object  in  the  growth  of 
cereals  is  to  obtain  the  grain  or  seed.  They  are  all 
annuals,  though  their  natural  period,  or  time  of  growth, 
differs,  certain  of  them  requiring  a  longer  time  for  their 
growth  and  maturity  than  others.  In  the  case  of  wheat, 
rye,  oats,  and  barley,  the  natural  period  of  vegetation  has 
been  changed  by  careful  selection  and  breeding,  so  that 
we  have  both  winter  and  spring  varieties,  the  former 
seeded  in  the  fall,  and  the  latter  in  the  spring.  The 
winter  varieties  of  wheat  and  rye,  and  the  spring  varie- 
ties of  oats  and  barley,  are  more  generally  grown.  Indian 
corn,  or  maize,  is  seeded  in  spring  only. 

The  Root  System.  —  In  the  cereals,  the  roots  branch 
just  below  the  surface,  and  each  shoot  produces  feeding- 
roots,  which  distribute  themselves  in  every  direction  to 
gather  food  and  directly  nourish  the  plant.  The  roots  of 
the  cereals,  though  they  are  regarded  as  shallow  feeders, 
also  penetrate  to  considerable  depths,  —  thirty-six  inches 
or  more,  —  the  depth  corresponding  to  some  extent  with 
the  period  of  growth,  winter  wheat  and  rye  showing  the 
deepest  roots,  and  oats  and  barley,  seeded  in  spring,  the 
shallowest. 

The  character  of  the  soil  also  exercises  an  influence 
in  this  respect.  The  deeper  the  root,  the  more  food  is 
acquired  ;  and  the  power  to  resist  drouth  and  other  un- 
favorable conditions  is  proportionately  increased.  A  soil 
too  dense  and  hard  prevents  the  penetration  and  develop- 


130         FIRST  PRINCIPLES  OF  AGRICULTURE. 

ment  of  the  root  system.  The  root  formation  of  the 
winter  cereals  is  encouraged  by  close  contact  with  moist 
earth,  hence  a  soil  of  a  compact  nature  is  desirable  for 
their  normal  growth  ;  loose,  shifting  sands  are  unfavor- 
able, moist  clay  loams  are  favorable. 

Method  of  Feeding.  —  The  general  tendency  of  the 
cereals  is  to  absorb  food  from  lower  layers  of  the  soil 
as  the  plant  grows  older ;  that  is,  the  roots  near  the 
plant  die ;  and  only  the  fibrous  roots  at  a  distance  and 
in  the  lower  layers  of  soil  possess  the  power  of  absorbing 
food :  hence,  to  ensure  maximum  and  continuous  growth 
throughout  the  whole  period  of  life,  the  entire  surface 
soil  must  be  enriched. 

Power  of  Acquiring  Pood.  —  The  cereals  are  able  to 
acquire  food  from  the  insoluble  phosphate  and  potash 
compounds  of  the  soil  in  a  greater  degree  than  root 
crops.  They  are  on  this  account  called  "  voracious  feed- 
ers." Oats  and  rye  possess  this  characteristic  more 
largely  than  wheat  or  corn.  Where  the  climate  is  suit- 
able, oats  and  rye  will  —  other  conditions  being  equal  — 
thrive  proportionately  better  on  poor  soil  than  wheat 
or  corn. 

These  crops  are  unable  to  feed  to  any  extent  upon 
the  insoluble  nitrogen  of  the  soil ;  they  absorb  the  nitro- 
gen necessary  chiefly  in  the  form  of  nitrates.  This  form 
of  nitrogen  must,  therefore,  be  directly  applied,  or  the 
soil  must  have  been  previously  supplied  with  nitrogenous 
materials  that  decay  readily. 

On  soils  well  supplied  with  mineral  constituents,  wheat, 
oats,  and  rye  —  both  because  they  are  uncultivated  crops, 
and  because   their  greatest  development  is  in  the  early 


SELECTION  OF  SEED;    FARM   CROPS.         131 

summer,  before  the  conditions  are  favorable  for  the  rapid 
change  of  organic  nitrogen  into  nitrates  —  are  more  bene- 
fited by  a  direct  application  of  nitrates  than  corn,  which, 
besides  being  a  cultivated  crop,  makes  its  greatest  growth 
in  late  summer,  when  the  decay  and  consequent  nitrifica- 
tion of  the  organic  matter  is  most  active. 

Soil  Exhaustion.  —  The  cereals  are  exhaustive  crops, 
because  the  food  constituents  gathered  are  largely  trans- 
ferred from  the  stem  and  leaf,  and  concentrated  in  the 
grain,  which  is  sold  from  the  farm. 

Forage  Crops ;  Grasses.  —  Nearly  all  varieties  of 
grasses  are  perennial,  though  the  length  of  life  depends 
upon  the  method  of  cropping  and  character  of  soil. 
Where  the  grass  is  allowed  to  seed,  it  dies  quicker  than 
when  it  is  pastured  or  cut  before  maturity,  because  the 
depth  of  root  is  measured  to  some  extent  by  the  length 
of  top.  On  poor,  dry  soils,  also,  the  life  is  shorter  than 
upon  moist  soils  of  fair  fertility. 

Methods  of  Growth.  —  The  grasses  send  out  their 
fibrous  roots  into  the  surface  soil  in  the  same  manner 
as  the  cereals,  though  they  differ  from  the  cereals  in 
forming  each  year  a  set  of  buds  just  below  the  surface 
of  the  ground,  which  become  active  in  the  late  summer, 
and  develop  new  shoots  and  roots ;  as  this  budding 
ceases,  the  plants  die.  Those  which  produce  the  great- 
est number  of  branches,  and  continue  the  process  for  a 
succession  of  years,  are  the  most  valuable  permanent 
grasses ;  those  that  form  their  branches  in  compact  tufts 
have  less  hold  upon  the  ground,  and  are  more  liable  to 
be  uprooted  by  animals,  and  to  be  destroyed  by  unfavor- 
able conditions  of  soil  and  season,  than  those  which  pos- 


132         FIRST  PRINCIPLES  OF  AGRICULTURE. 

sess  a  loose-branching  system.  A  mixture  of  the  tuft 
and  loose-growing  grasses  is,  as  a  rule,  better  than  either 
singly. 

Food  Requirements.  —  The  chief  object  in  the  growth 
of  grasses  is  to  obtain  the  nutrition  contained  in  leaf 
and  stem  in  the  form  of  pasture,  forage,  or  hay.  Nitro- 
gen, which  promotes  this  form  of  growth,  is  an  important 
constituent,  and  it  is  essential  to  provide  a  liberal  sup- 
ply, either  directly,  as  nitrate  of  soda,  or  in  organic  forms, 
which  decay  more  or  less  rapidly. 

The  grasses  resemble  the  cereals  in  their  power  of  ac- 
quiring mineral  food ;  hence  clay  soils,  which  are  rich 
in  the  minerals,  are  naturally  well  adapted  for  their 
growth.  Except  when  seed  is  grown,  or  hay  is  sold, 
the  grasses  are  not  regarded  as  exhaustive  crops. 

Clovers.  —  The  clovers  are  grouped  with  the  grasses 
because  usually  grown  for  the  same  purpose,  —  for  pas- 
ture, forage,  or  hay.  They,  however,  belong  to  a  family 
of  plants  which  possesses  characteristics  very  different 
from  the  grasses,  both  in  reference  to  method  of  growth 
and  composition  of  product.     The  varieties  usually  grown 

are :  — 

Scarlet  or  Crimson  Clover,        an  annual. 

Red  or  Broad  Clover,  a  biennial. 

Alsike  or  Swedish  Clover,        a  triennial. 

White  or  Dutch  Clover,  a  perennial. 

Of  these  the  red  and  white  are  more  extensively  grown 
than  the  others. 

Methods  of  Growth.  —  The  red,  alsike,  and  crimson 
clovers  all  possess  a  tap-root  which  penetrates  downward 
to  considerable  depths;  and  as  it  descends  it  throws  out 
root-fibres  into  the  different  layers  of  soil;  these  gather 


SELECTION  OF  SEED;    FARM   CROPS.  133 

the  food  which  passes  through  the  tap-root  into  the 
branches.  The  branches  are  formed  from  buds,  which 
depend  for  their  food  upon  the  tap-root  and  its  feeders, 
the  fibrous  roots.  From  spring  seedings  of  clover  the 
buds  begin  to  develop  in  the  late  summer,  lie  dormant 
through  the  winter,  branch  forth  in  the  spring,  and  de- 
velop into  the  mature  plant. 

With  the  exception  of  the  annual  crimson  clover,  the 
process  continues  two,  three,  or  more  years,  as  the  case 
may  be.  Crimson  clover  is  usually  seeded  in  the  late 
summer  or  fall;  it  develops  the  buds  in  the  spring,  and 
dies  after  maturing  the  plant. 

In  white  clover  the  stem  creeps  along  just  under  the 
surface,  throwing  out  roots  at  frequent  intervals,  which 
penetrate  the  soil  and  gather  food  that  is  carried  directly 
into  the  stem,  and  by  it  to  the  branches. 

Power  of  Acquiring  Food.  —  The  clovers  readily  ac- 
quire food  from  the  mineral  constituents  of  the  soil,  and 
differ  from  the  cereals  in  being  able  to  acquire  their  nitro- 
gen from  the  air;  hence  on  most  soils  the  application  of 
this  element  is  not  so  essential  for  their  growth.  The 
clovers  demand  an  abundance  of  potash  and  lime. 

Soil  Improvers.  —  The  clovers  are  not  exhaustive 
crops,  but  rather  soil  improvers.  The  nitrogen  gathered 
and  stored  as  organic  substance  in  roots  and  stubble  en- 
riches the  soil  in  humus  and  nitrogen,  while  the  method 
of  growth,  viz.,  the  formation  of  large  tap-roots,  which 
penetrate  deeply,  materially  improves  the  physical  char- 
acter of  soils. 

Root  Crops.  —  Turnips,  carrots,  parsnips,  beets,  and 
mangels  are  biennials.     The  first  year  or  period  of  growth 


134        FIRST  PRINCIPLES    OF  AGRICULTURE. 

is  the  storage  or  vegetative  period,  and  the  second,  the 
period  of  seed-making. 

Root  crops  are  all  provided  with  tap  or  storage  roots, 
and  hence  they  flourish  well  only  in  deep,  mellow  soils. 
They  are  supplied  with  absorbing  roots,  which  spring 
mainly  from  the  lower  end,  spread  into  the  soil,  and 
gather  the  food.  The  chief  supply  of  food  is  needed  late 
in  the  season,  when  the  formation  of  tap-root  is  most 
rapid. 

These  plants  cannot  make  ready  use  of  the  insoluble 
mineral  constituents  of  the  soil ;  hence,  in  order  to  insure 
full  crops,  they  must  be  liberally  supplied  with  available 
food.  Of  the  three  classes  of  fertilizing  materials,  the 
phosphates  are  especially  suitable  for  turnips,  while  the 
slower-growing  beets  and  carrots  require  an  abundance 
of  nitrogen  in  quickly  available  forms. 

Tuber  Crops.  —  The  white  potato  tuber  is  not  a  root, 
but  an  enlarged  underground  stem.  The  true  feeding- 
roots  are  produced  by  the  underground  portion  of  the 
main  stem.  The  extensive  growth  of  the  plant  under- 
ground requires  that  the  soil  shall  be  loose  and  open, 
in  order  to  permit  the  free  entrance  and  circulation  of 
both  air  and  water.  Potatoes,  like  root  crops,  do  not 
possess  strong  foraging  powers.  The  food  must  be  in  a 
soluble  and  available  condition,  in  order  to  insure  maxi- 
mum production.  Where  soils  are  suitable,  potash  seems 
to  be  the  ingredient  especially  useful  in  the  manures 
applied,  as  it  is  a  potash-demanding  plant. 

The  sweet-potato  tuber  is  an  enlarged  root,  and  not  a 
stem,  as  is  the  case  with  the  white  potato.  The  plant 
is  especially  adapted  to  warm,  dry  soils;    and,  while  it 


SELECTION  OF  SEED;    FARM  CROPS.  135 

thrives  well  on  soils  too  poor  and  sandy  for  the  white 
potato,  it  must  be  well  supplied  with  the  mineral  con- 
stituents, particularly  potash. 

Market-Garden  Crops.  —  These  include  a  large  num- 
ber which  are  distinguished  not  so  much  by  their  place 
or  method  of  growth  as  the  object  of  their  production; 
viz.,  earliness  and  succulence,  rather  than  maturity  of 
crop.  Lettuce,  beets,  spinach,  radishes,  onions,  cabbage, 
turnips,  celery,  asparagus,  tomatoes,  egg-plant,  cucumbers, 
melons,  peas,  beans,  sweet  corn,  and  many  others,  are 
included  under  market-garden  crops. 

To  accomplish  the  two  particular  objects  of  their  growth 
requires  a  deep,  warm  soil,  well  supplied  with  vegetable 
matter  and  with  available  forms  of  plant-food.  Since 
nitrogen  is  the  element  which  encourages  and  stimulates 
leaf  and  stem  growth,  its  application,  particularly  in  the 
form  of  nitrates  which  are  immediately  available,  is  es- 
pecially useful  for  all  of  these  crops;  and  though  peas 
and  beans  belong  to  the  legume  family,  they  are  materi- 
ally benefited  in  their  early  growth  by  a  supply  of  soil 
nitrogen. 

Fruit  Crops.  —  These  differ  from  other  crops  in  that 
there  must  be  a  longer  season  of  preparation,  in  which 
the  growth  shall  be  so  directed  as  to  prepare  the  tree  for 
the  proper  development  of  a  different  kind  of  product; 
namely,  the  fruit.  The  fruit,  too,  differs  very  materially 
in  its  character  from  that  of  ordinary  farm  crops,  in  that 
its  growth  and  development  require  a  whole  season;  it  is 
necessary  that  there  shall  be  a  constant  transfer  of  the 
nutrition  from  the  tree  to  the  fruit  throughout  the  grow- 
ing-season.    The  growth  for  each  succeeding  year  of  both 


136         FIRST  PRINCIPLES  OF  AGRICULTURE. 

tree  and  fruit  is,  too,  dependent  upon  the  nutrition  stored 
up  in  the  bud  and  branches,  as  well  as  that  which  may 
be  derived  directly  from  the  soil. 

Soils  that  are  naturally  well  adapted  for  fruit- 
growing must  possess  a  good  physical  character;  that 
is,  they  must  be  sufficiently  open  and  porous  to  permit 
the  penetration  and  growth  of  the  roots,  as  well  as  a 
free  movement  of  air  and  water,  and  they  must  contain 
nitrogen  and  the  mineral  constituents,  lime,  potash,  and 
phosphoric  acid,  in  considerable  amounts. 

The  first  object  should  be  to  secure  a  good  tree,  though 
it  is  not  wood  growth  alone  that  should  be  kept  in  mind, 
but  the  kind  of  growth  as  well ;  that  is,  it  must  not  only 
be  vigorous,  but  well  matured.  Well-grown  trees  some- 
times produce  poor  fruit,  but  poor  trees  never  produce 
good  fruit. 

Manures  for  Fruits.  —  In  the  first  place,  there  should 
be  sufficient  nitrogen  to  provide  for  an  abundant  leaf 
growth  early  in  the  season,  since  the  tree  and  fruit  are 
dependent  for  food  both  upon  the  leaves  and  upon  the 
roots.  There  should  be  an  abundance  of  potash  and  phos- 
phoric acid  and  lime,  in  order  to  secure  a  normal  and 
solid  growth  of  stem  and  branch,  which  carry  the  fruit- 
spurs,  and  the  food  necessary  for  their  first  development 
in  the  spring,  as  well  as  to  provide  for  the  proper  growth 
and  ripening  of  the  fruit. 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD  137 


CHAPTER  XII. 

The  Growth  of  Animals ;  The  Constituents  of  Animals  and  Ani- 
mal Food ;  The  Character  and  Composition  of  Fodders  and  Feeds. 

In  our  study  of  the  growth  of  plants,  it  was  shown 
that,  with  the  exception  of  the  food  stored  in  the  seed, 
the  plant  was  built  up  of  single  chemical  elements,  and 
that  these  were  derived  from  sources  outside  of  itself, 
viz.,  the  atmosphere  and  soil,  and  formed  by  the  living 
plant  into  organized  plant  substances.  The  growing  of  a 
plant,  therefore,  is  a  constructive  process ;  elements  that 
exist  separately  are  gathered  from  different  sources,  and 
combined  and  fixed  in  special  forms. 

The  growth  of  the  animal  is  more  complicated.  It  is 
built  up  and  nourished  by  the  consumption  of  substances 
ready  formed  in  plants,  or  which  have  been  derived  from 
them.  It  is  a  double  process,  —  first,  a  disorganizing,  or 
tearing  apart  of  these  substances  formed  in  the  plant; 
and  second,  a  building  or  forming  process  in  which  they 
are  brought  together  again,  and  fixed  in  the  form  of 
flesh  and  bone. 

Composition  of  the  Animal  Body.  —  The  animal 
body,  therefore,  is  composed  of  substances  or  elements 
common  to  the  plants  from  which  it  was  directly  or  in- 
directly derived.  It  may  be  divided,  first,  into  two 
classes  of  products,  water  and  dry  substance. 


138         FIRST  PRINCIPLES  OF  AGRICULTURE. 

Water.  —  This  is  an  important  constituent.  It  is 
essential  to  the  proper  distribution  of  the  nourishing  fluids 
throughout  the  system,  and  usually  constitutes  more  than 
one-half  of  the  total  weight  of  the  live  animal.  As  is 
the  case  with  plants,  it  is  contained  in  the  greatest 
amounts  in  the  young  or  immature,  and  decreases  as 
growth  proceeds,  and  maturity  is  reached.  It  is  possi- 
ble to  remove  it  from  animal  substances  without  entirely 
destroying  their  form,  thus  differing  from  the  constitu- 
ents that  constitute  the  dry  matter;  these  cannot  be 
removed  without  destroying  the  character  of  the  sub- 
stances themselves.  Here,  too,  is  a  striking  analogy 
between  plant  and  animal. 

Dry  Matter.  —  This  may  also  be  divided  into  two 
general  classes,  —  first,  that  which  is  organic  or  volatile, 
or  that  portion  capable  of  being  destroyed,  or  converted 
into  gaseous  substances,  by  means  of  heat ;  and  second, 
ash  or  inorganic,  mineral,  or  non-volatile,  or  that  por- 
tion which  cannot  be  destroyed  or  dispelled  by  means 
of  heat. 

Organic  Substances.  —  These  are  usually  divided 
into  two  general  classes,  —  first,  non-nitrogenous,  or  those 
free  from  nitrogen,  consisting  of  carbon,  hydrogen,  and 
oxygen  only ;  and  second,  nitrogenous,  those  containing 
nitrogen  in  addition  to  the  carbon,  hydrogen,  and  oxygen. 

Non-Nitrogenous  Substances.  —  The  chief  of  these  is 
fat,  a  substance  extremely  rich  in  the  element  carbon, 
and  a  very  important  constituent  of  food.  It  is  found 
distributed  throughout  the  various  organs  of  the  animal 
body,  though  mainly  enclosed  in  cells  on  the  kidneys 
and  between  the  muscular  fibres.     The  fat  contained  in 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD.       139 

the  various  kinds  of  animals,  which  is  a  whitish,  oily 
substance,  differs  but  little  in  appearance,  though  some- 
what in  composition. 

Nitrogenous  Substances.  —  These  consist  chiefly  of 
carbon,  hydrogen,  oxygen,  and  nitrogen,  though  phos- 
phorus and  sulphur  are  always  present  in  small  amounts. 
This  class  may  be  subdivided  into  three  groups :  1.  Albu- 
minoids ;  2.  Gelatinoids ;  3.  Horny  Matter. 

Albuminoids.  —  These  are  the  most  important,  because 
animal  life  is  dependent  chiefly  upon  them  and  the  or- 
gans composed  of  them,  and  because  they  furnish  the 
material  out  of  which  the  other  groups  are  formed.  They 
are  found  in  various  forms  in  the  body,  the  chief  of 
which  are  albumen,  fibrin,  and  casein.  These,  while  dif- 
fering widely  in  appearance,  agree  in  their  chemical  com- 
position, in  that  each  in  a  pure,  dry  state  contains  about 
sixteen  per  cent  of  nitrogen,  and  from  one  to  one  and 
five-tenths  per  cent  of  sulphur;  albumen  is  represented 
by  the  white  of  egg,  fibrin  by  the  white  solid  remaining 
after  the  red  color  of  coagulated  blood  is  washed  out, 
while  casein  forms  the  basis  of  cheese. 

Gelatinoids.  —  These  form  the  nitrogenous  substances 
of  bone,  skin,  and  cartilage,  and  the  connective  tissue  of 
the  animal  body.  They  may  be  extracted  by  boiling 
with  water ;  the  resultant  product  is  glue.  Their  com- 
position is  similar  to  the  albuminoids,  in  that  on  the 
average  they  contain  about  sixteen  per  cent  nitrogen, 
the  cartilage  containing  less,  and  the  bones  and  skin 
more,  nitrogen  than  the  albuminoids. 

Horny  Matter.  —  The  hair,  horn,  hoofs,  claws,  nails, 
wool,  and  feathers  are  constituted  mainly  of  horny  matter. 


140         FIRST  PRINCIPLES  OF  AGRICULTURE. 

The  composition  of  horny  matter  is  quite  uniform,  and 
is  similar  to  albumen  in  content  of  nitrogen,  though  con- 
taining more  sulphur. 

Inorganic  Matter  or  Ash.  —  The  ash  constitutes  a 
very  small  part  of  the  total  weight  of  animals.  It  ranges 
from  one  and  eight-tenths  per  cent  to  three  per  cent  in 
swine,  and  from  four  and  five-tenths  per  cent  to  five 
per  cent  in  cattle.  The  ash  constituents  are  greatest  in 
lean  animals,  and  least  in  fat  animals.  Of  the  different 
parts  of  animals,  the  dried  bones  contain  the  largest 
portions,  reaching  fifty  per  cent  in  the  bones  of  young 
animals,  and  as  high  as  eighty-five  per  cent  in  mature 
animals.  Bone-ash  consists  almost  entirely  of  phosphate 
of  lime.  Other  very  important  constituents  of  the  ash 
are  potash,  soda,  and  chlorine. 

Animal  Food.  —  The  animal  body,  consisting  of  the 
two  classes  of  substances,  the  nitrogenous  and  non-nitro- 
genous, demands  the  same  classes  from  the  food.  These 
latter  correspond  in  kind  to  those  described  as  contained 
in  the  animal  body,  with  the  addition  of  carbohydrates ; 
viz.,  1.  Albuminoids ;  2.  Fats ;  3.  Carbohydrates ;  4.  Min- 
eral Salts. 

Albuminoids.  —  The  albuminoids  of  a  feed  include 
vegetable  albumen  and  fibrin,  as  well  as  other  substances 
which  resemble  in  composition  the  albuminoids  of  the 
animal  body.  The  term  "  protein "  is  frequently  used 
to  designate  this  class  of  substances  when  contained  in 
food. 

The  various  albuminoids  vary  somewhat  in  their  com- 
position. They  are  distinguished  by  their  high  and  quite 
uniform  content  of  nitrogen ;  and,  though  differences  exist 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD.       141 

in  them,  it  is  believed  that  they  are  quite  uniform  in 
their  value  as  nutrients.  They  are  not  only  the  most 
important  of  the  food  compounds,  but  are  indispensable, 
as  they  are  the  sole  source  directly  of  the  albuminoids 
in  the  body  of  the  plant-eating  animal. 

Other  nitrogenous  compounds  are  also  contained  in 
small  quantities  in  most  plants,  though  they  are  rela- 
tively unimportant  as  sources  of  nourishment. 

Fat.  —  The  fat  or  oil  contained  in  plants  agrees  closely 
in  chemical  composition  with  that  contained  in  animals. 
Fats  contain  a  much  larger  proportion  of  carbon,  and 
less  of  oxygen,  than  the  carbohydrates.  Fat  exists  in 
all  plants,  and  in  some  seeds,  as  flax  and  cotton,  in  such 
quantities  as  to  make  them  of  considerable  commercial 
importance  as  sources  of  oil. 

Carbohydrates.  —  These  agree  closely  in  composition. 
They  consist  of  carbon,  hydrogen,  and  oxygen  only,  and 
derive  their  name  from  the  fact  that  the  hydrogen  and 
oxygen  in  them  always  exist  in  the  same  proportions  as 
they  exist  in  water.  Cellulose,  or  woody  fibre,  and  starch 
are  the  most  abundant  of  the  carbohydrates,  though  the 
sugars  and  gums  are  also  well-known  members  of  this 
group. 

Cellulose  is  the  substance  which  composes  the  cell  walls 
or  woody  part  of  the  plant.  It  is  seldom  pure,  except  in 
young  plants.  In  trees  where  great  strength  is  needed, 
the  cell  walls  become  thick  and  hard,  and  joined  with  the 
cellulose  is  a  harder  substance  called  "  lignin."  In  ordi- 
nary farm  plants  the  cellulose  exists  in  greater  propor- 
tions in  the  ripe  straw,  and  in  the  stems  ami  husks  of  the 
various  plants,  than  in  the  seeds.     This  fibrous  material 


142        FIRST  PRINCIPLES  OF  AGRICULTURE. 

is  usually  white  in  color,  and  is  odorless  and  tasteless. 
Manufactured  flax  and  cotton,  and  unsized  paper  derived 
from  them,  are  good  examples  of  nearly  pure  cellulose. 
It  is  not  readily  soluble,  and  is  capable  of  only  partial 
digestion.  It  is  identical  with  starch  in  chemical  com- 
position, and  may  be  converted  first  into  dextrine,  then 
into  grape  sugar,  by  suitable  treatment  with  acids  or 
alkalies. 

Starch  is  a  very  abundant  substance ;  it  is  found  in  all 
plants,  and  in  nearly  all  parts  of  them.  The  cereal 
grains,  and  the  dry  matter  of  root  and  tuber  crops,  are 
especially  rich  in  this  substance;  and  because  of  its 
abundance  and  ease  of  digestion  it  is  one  of  the  most 
important  of  the  non-nitrogenous  substances.  It  is  readily 
converted  into  dextrine  and  grape  sugar  by  treatment 
with  acids ;  in  fact,  the  grape  sugar  or  glucose  of  com- 
merce is  largely  derived  from  the  starch  of  corn. 

Sugars  are  of  four  kinds,  —  cane,  milk,  grape,  and  fruit 
sugar:  these  differ  but  little  in  composition;  all  resem- 
ble each  other  in  their  properties.  Cane  sugar  is  derived 
from  sugar-cane  and  sugar-beet,  and  milk  sugar  from 
the  milk  of  the  cow,  while  grape  and  fruit  sugars  usu- 
ally occur  together  in  the  juices  of  plants,  sweet  fruits, 
and  in  honey.  These  are  all  readily  soluble  in  water, 
and  easily  digested ;  and,  although  occurring  in  small 
quantities  in  ordinary  feeds,  they  are  very  important, 
because  formed  in  large  quantities  from  other  carbo- 
hydrates in  digestion. 

The  gums  exist  in  small  amounts  in  plants  used  for 
animal  food,  and  are  relatively  unimportant  food  com- 
pounds. 


GROWTH  OF  ANIMALS  ;    ANIMAL  FOOD.       143 

Mineral  Salts.  —  These  are  contained  in  ordinary  fod- 
ders in  sufficient  quantities  to  supply  the  needs  of  the 
animal  body. 

The  Chemical  Analyses  of  Animal  Poods.  —  By 
means  of  chemical  analyses  the  amount  of  moisture  and 
of  the  various  groups  of  food  compounds  described  as 
contained  in  a  food,  are  determined;  viz.,  albuminoids, 
fats,  carbohydrates,  and  mineral  matter.  This  grouping 
is,  however,  quite  incomplete,  though  serving  an  excel- 
lent purpose  in  indicating  feeding  value,  and  as  a  means 
by  which  a  comparison  may  be  made  of  the  various  food 
products. 

Water  or  Moisture.  —  Water  or  moisture  is  deter- 
mined by  drying  at  a  temperature  of  boiling  water. 

Crude  Protein.  —  The  nitrogenous  substances  are  found 
by  determining  the  nitrogen,  and  multiplying  the  percen- 
tage found  by  the  factor  6.25,  on  the  assumption  that 
all  of  the  nitrogen  is  in  the  form  of  albuminoids,  which 
contain  on  the  average  sixteen  per  cent  of  nitrogen.  The 
substance  found  in  this  manner  is  called  "crude  protein." 
In  many  cases,  however,  the  nitrogenous  substances,  not 
in  the  form  of  albuminoids,  as  amides  and  amines,  and 
contained  in  considerable  amounts  in  immature  plants, 
are  determined  separately  and  deducted  from  the  total 
crude  protein  found,  in  which  cases  the  results  are  stated 
as  "  true  albuminoids  "  and  as  "  non-albuminoids." 

Fat.  —  The  content  of  fat  is  determined  by  extract- 
ing with  ether,  or  other  solvents,  and  the  result  is  stated 
as  crude  fat  or  extractive  matter,  since  other  substances, 
as  gums  and  coloring  matter,  are  extracted  to  some  ex- 
tent along  with  the   fat.     These   may,  however,  be  sep- 


144        FIRST  PRINCIPLES  OF  AGRICULTURE. 

arated;  and  when  this  is  done  the  result  is  stated  as 
"pure  fat." 

Crude  Fibre  or  Cellulose.  —  Crude  fibre  or  cellulose 
is  determined  by  boiling  the  substance  with  weak  acids 
and  alkalies,  which  dissolve  the  other  constituents  con- 
tained in  it.  The  residue  is  called  "  crude  fibre,"  rather 
than  "  cellulose,"  since  it  contains  all  the  woody  sub- 
stance of  the  plant,  including  "lignin." 

Ash  or  Mineral  Matter.  —  The  ash  or  mineral  mat- 
ter is  determined  by  carefully  burning  the  substance,  by 
which  means  the  organic  vegetable  matter  is  completely 
removed. 

Nitrogen-free  Extract.  —  The  nitrogen-free  extract, 
which  includes  starch,  sugar,  and  gums,  is  usually  deter- 
mined by  difference;  that  is,  by  subtracting  the  sum  of 
the  water,  crude  protein,  crude  fat,  crude  fibre,'  and  crude 
ash  from  one  hundred.  This  group,  together  with  the 
crude  fibre,  makes  the  total  carbohydrates. 

Statement  of  Analysis. — An  example  of  the  usual 
method  of  reporting  an  analysis  of  a  food  is  here 
given :  — 

Water 15.3  per  cent. 

Crude  Fat  (extractive  matter) 3.3 

Crude  Protein  (nitrogenous  substances)    ....  12.3 

Crude  Ash  (mineral  matter) 6.2 

Crude  Fibre  (cellulose  and  lignin) 24.8 

Nitrogen-free  Extract  (starch,  sugars,  gums,  etc.)  38.1 

Functions  of  the  Animal  Body.  —  The  object  of 
feeding  is  to  furnish  material  for  maintaining  life,  and 
for  building  up  the  animal  body;  and  each  of  the  com- 
pounds of  the  food  exerts  a  specific  function  in  the  pro- 
cess,   though    alone    they  are    incapable    of    completely 


GROWTH  OF  ANIMALS ;    ANIMAL  FOOD.       145 

nourishing  the  body  and  maintaining  life.  The  change 
of  the  food  compounds  or  constituents  into  similar 
animal  products  is  accomplished  in  the  living  animal 
by  a  series  of  what  are  termed  "nutritive  processes  or 
functions,"  and  include  digestion,  circulation,  respiration, 
secretion,  and  absorption. 

Digestion.  —  By  digestion  the  solid  matter  of  the  food 
is  brought  into  a  form  capable  of  being  absorbed  by 
the  blood.  Soluble  food  compounds,  as  sugar,  are  ab- 
sorbed without  digestion.  Digestion  is  accomplished  by 
means  of  the  digestive  organs,  —  the  mouth,  stomach,  and 
intestines.  In  the  mouth  the  food  is  ground  fine  and 
mixed  with  the  saliva,  which,  besides  softening  the  food, 
makes  it  alkaline,  and  starts  a  fermentation,  which 
changes  the  starch  into  sugar;  when  the  masticated 
food  passes  into  the  stomach  —  the  fourth  stomach  in 
the  case  of  animals  that  chew  their  cuds  —  it  comes  in 
contact  with  the  gastric  juice.  This  is  an  acid  substance 
which  acts  chiefly  upon  the  albuminoids,  converting  them 
into  substances  called  "peptones,"  which  are  capable  of 
passing  through  the  lining  membranes  of  the  stomach. 
The  food  remains  in  the  stomach  a  sufficient  time  to 
bring  every  portion  in  contact  with  the  gastric  juice;  it 
then  passes  into  the  first  intestine,  where  it  meets  with 
other  alkaline  secretions,  pancreatic  juice  and  bile,  which 
complete  the  digestion  of  the  starch,  albuminoids,  and 
fat.  The  absorption  of  the  dissolved  constituents  of  the 
food  now  remaining  takes  place  finally  in  the  small  in- 
testines; the  soluble  product  passes  into  the  blood,  which 
then  nourishes  the  whole  body ;  the  undigested  portion 
is  expelled  in  the  form  of  manure. 


146        FIRST  PRINCIPLES   OF  AGRICULTURE. 

Respiration  or  Breathing.  —  The  air  taken  into  the 
lungs  consists  chiefly  of  oxygen  and  nitrogen.  When  it 
passes  out  it  has  lost  about  one-quarter  of  its  oxygen, 
and  also  contains  a  large  amount  of  carbonic  acid;  the 
oxygen  has  been  absorbed  by  the  blood,  and  the  carbonic 
acid  carried  out  is  the  product  of  the  oxidation  or  burn- 
ing of  old  tissue.  By  this  oxidation  the  heat  of  the 
body  is  maintained,  and  kept  in  a  healthy  condition. 

Excretion.  —  The  products  of  oxidation  of  the  animal 
tissues  are  carbonic  acid,  water,  urea,  and  mineral  salts. 
The  carbonic  acid,  as  already  seen,  is  chiefly  removed  by 
the  lungs,  and  to  some  extent  by  the  skin;  the  urea  and 
salts  are  removed  by  the  kidneys,  and  the  water  by  all 
of  the  organs  of  excretion. 

What  is  Food  ?  —  It  is  thus  seen  that,  in  the  processes 
of  life  the  substances  contained  in  the  food  are  changed 
into  animal  product,  and  that  this  change  is  always 
accompanied  by  loss.  Any  material  capable  of  replacing 
this  loss,  in  whole  or  in  part,  is  called  a  "fodder"  or  a 
"feed;"  and  any  single  compound,  like  albumen  or  fat, 
is  called  a  "nutrient."  The  first  essential  in  a  feed  is, 
then,  nutritious  compounds ;  these  must,  however,  be  pal- 
atable, that  is,  capable  of  being  eaten,  and  must  possess 
a  certain  bulk,  in  order  to  properly  distend  the  stomach 
and  supply  the  needs  of  the  animal  in  this  respect,  and 
must  be  capable  of,  at  least,  partial  digestion. 

Fodders  and  Feeds.  —  Common  usage  has  divided 
animal  foods  into  two  classes,  coarse  fodders  and  con- 
centrated fodders,  or  fodders  and  feeds.  By  fodders  are 
commonly  understood  those  products  whose  chief  charac- 
teristic  is   bulk ;   hay,  cornstalks,   and   straw,   belong  to 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD.        147 

this  class.  By  feeds  are  understood  the  more  highly 
concentrated  materials  ;  the  cereal  grains,  buckwheat,  peas, 
and  the  mill  products  belong  to  this  class.  Thus,  fod- 
ders may  be  classified  as  hay,  straws,  green  fodders,  roots, 
and  tubers ;  and  feeds  as  grains,  mill-feeds,  and  refuse 
products. 

Hay.  —  Hay  produced  from  the  true  grasses,  as  tim- 
othy, orchard  grass,  herd's-grass,  and  others,  is  bulky,  and 
is  characterized  by  a  high  content  of  carbohydrates,  in- 
cluding crude  fibre,  and  a  low  content  of  crude  fat  and 
crude  protein;  that  made  from  the  clovers,  —  red,  alsike, 
and  crimson,  —  while  also  bulky,  is  much  richer  in  protein 
than  the  others.  Hay  is  variable  in  its  composition;  its 
quality  depending  upon  the  kind  or  variety,  the  character 
of  soil,  the  stage  of  growth  at  time  of  cutting,  and  the 
method  of  curing.  The  chief  influence  of  the  kind  of  soil 
is  upon  the  content  of  crude  protein ;  the  richer  the  soil, 
the  richer  the  hay  is  likely  to  be  in  this  substance. 

Early  or  Late  Cut  Hay.  —  Early  cut  hay  is  also  richer 
in  crude  protein,  and  poorer  in  crude  fibre,  than  late  cut : 
for,  although  an  increase  in  the  weight  of  dry  matter  may 
occur,  it  is  chiefly  in  the  substance  cellulose,  or  crude 
fibre ;  besides,  a  material  loss  of  the  more  nutritious  com- 
pounds is  likely  to  take  place  if  it  is  allowed  to  ripen 
thoroughly. 

The  Best  Time  for  Cutting  Hay.  —  The  best  time  for 
cutting  is  when  the  plants  are  in  blossom  ;  since  little,  if 
any,  food  is  absorbed  from  the  soil  after  that  period.  Hay 
that  has  been  subjected  to  frequent  rains,  and  consequent 
increased  handling,  suffers  great  loss,  which  falls  almost 
entirely  upon  the  most  nutritious  parts.     This  is  particu- 


148  FIRST  PRINCIPLES  OF  AGRICULTURE. 

larly  true  of  clover  hay ;  the  leaves,  which  are  subject  to 
loss  in  handling,  contain  the  highest  content  of  protein, 
while  the  stems  consist  largely  of  cellulose  or  fibre.  The 
loss  by  repeated  wetting,  which  may  reach  as  high  as 
forty  per  cent  of  the  dry  matter,  consists  almost  entirely 
of  the  class  carbohydrates.  Crude  fibre  suffers  but  little 
loss. 

Corn  grown  for  fodder,  from  which  such  ears  as  are 
formed  are  not  removed,  corresponds  more  nearly  with 
hay  in  composition  than  with  straw  and  stalks,  though 
containing  much  less  crude  fibre. 

Straw  and  Stalks.  —  These  possess,  in  a  greater  degree 
than  hay,  the  characteristic  bulk,  since  the  nutritive  mat- 
ter that  first  existed  in  the  straw  has  passed  into  the  seeds, 
which  have  been  removed;  the  straw  is  consequently 
poorer  in  protein  and  carbohydrates,  and  richer  in  fibre, 
than  good  hay,  and  shows  a  proportionately  lower  rate  of 
digestibility.  The  food  compounds  in  straw  after  diges- 
tion are,  however,  quite  as  valuable,  and  serve  their 
purpose  quite  as  well  as  those  contained  in  hay.  The 
variations  in  composition  of  straw  are  due  to  the  same 
conditions  as  those  which  affect  hay. 

Wheat  and  rye  straw  are  poorer  in  protein  and  fat,  and 
richer  in  the  carbohydrates  and  fibre,  and  are  coarser 
and  harsher,  than  oat  straw.  Corn  stalks  or  stover  —  the 
stalks  from  which  the  ears  have  been  removed  —  are  richer 
in  protein  and  fat,  and  poorer  in  fibre  and  carbohydrates, 
than  the  straws ;  they  compare  fairly  well  with  hay  in 
their  composition.  All  of  these  products,  however,  if  prop- 
erly cured,  serve  an  excellent  purpose  in  furnishing  both 
bulk  and  nutritious  compounds,  and  should  be  utilized. 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD.         149 

Green  Fodders.  —  Green  fodders  are  watery  in  char- 
acter, though  they  contain  the  same  proportion  of  food 
compounds  as  the  hay  made  from  them,  provided  no  loss 
occurs  in  making  the  hay.  The  disadvantage  of  handling 
the  large  amounts  of  water  contained  in  green  fodders  is 
frequently  balanced  by  a  decreased  loss  in  dry  matter,  due 
to  handling  in  a  green  state,  and  by  an  increased  palata- 
bility  and  succulence. 

Ensilage.  —  Ensilage  is  fodder  corn,  clover,  rye,  or  other 
green  food,  preserved  in  such  a  manner  —  usually  in  air- 
tight buildings  called  silos  —  as  to  retain  in  large  part 
all  of  the  qualities  of  the  original  product.  It  is  highly 
regarded,  particularly  on  dairy  farms,  where  succulence 
in  a  fodder  is  a  matter  of  importance.  The  losses  due 
to  fermentation  occurring  in  the  silo  or  pit  are  con- 
siderable, and  fall  chiefly  upon  the  class  carbohydrates; 
though,  according  to  experiments  already  conducted,  the 
total  loss  is  less  by  this  method  than  by  curing  in  the  field. 

Tubers  and  Roots.  —  These  all  contain  large  amounts 
of  water,  ranging  from  seventy-five  per  cent  in  potatoes 
to  over  ninety  per  cent  in  turnips.  Their  value  as  food 
depends,  perhaps,  quite  as  much  upon  their  succulence, 
palatability,  high  rate  of  digestibility,  and  good  effect  upon 
the  animal  system,  as  upon  the  food  constituents,  which 
consist  almost  entirely  of  carbohydrates. 

Cereal  Grains.  —  The  grains  or  seeds  of  the  cereals  are 
the  most  important  of  the  feeds.  They  are  especially 
suited  for  all  kinds  of  farm  animals,  and  for  the  various 
purposes  of  feeding.  They  are  rich  in  the  three  groups 
of  food  compounds  described,  are  reasonably  constant 
in  composition,  and  possess    a  high  rate  of   digestibility. 


150  FIRST  PRINCIPLES   OF  AGRICULTURE. 

Corn  and  oats  are  the  cereal  grains  most  largely  used  for 
animal  food.  Of  these  corn  is  richer  in  carbohydrates, 
and  is  used  to  the  greatest  extent  for  fattening,  and  oats 
almost  exclusively  as  a  food  for  horses,  for  which  it  is 
peculiarly  adapted,  both  in  bulk  and  in  proportion  of 
food  constituents. 

Mill-Feeds  and  Refuse  Products.  —  These  consist 
of  the  ground  grains  of  corn,  oats,  and  rye,  either  singly 
or  mixed,  and  the  residues  of  grains  or  seeds  after  their 
use  for  other  purposes  has  been  accomplished.  The  latter 
differ  from  the  whole-grain  feeds  in  showing  a  higher 
content  of  nitrogenous  matter. 

Bran  and  Middlings.  —  Bran  and  middlings  derived  in 
the  manufacture  of  flour  consist  of  the  outer  coverings 
of  the  grains  used,  mixed  with  more  or  less  of  the  germ, 
and  are  richer  in  fat,  protein,  and  ash  than  the  original 
grain,  the  flour  containing  a  much  larger  proportion  of 
the  carbohydrates.  They  are  very  useful  when  fed  in 
connection  with  the  fodders,  since  they  supply  in  a  con- 
centrated form  the  nutrients  usually  deficient  in  these 
products.  The  middlings  are,  on  the  whole,  better  than 
bran,  since  they  contain  less  crude  fibre  and  more  carbo- 
hydrates. Both  bran  and  middlings  vary  somewhat  in 
composition,  due  to  differences  in  methods  of  manufac- 
ture, and  also  to  variations  in  the  composition  of  the 
original  product ;  these  variations  are,  however,  less 
marked  than  those  which  occur  in  the  various  fodders. 

Brewers'  Grains.  —  Brewers'  grains,  which  represent 
the  bran  of  barley,  and  malt  sprouts,  which  are  the  dried 
germs  of  the  same  grain,  are  derived  in  the  manufacture 
of  beer  from  barley.     The  grains  when  they  have  served 


GROWTH  OF  ANIMALS;    ANIMAL  FOOD.        151 

the  purpose  of  the  brewer  are  very  wet,  containing,  on  the 
average,  seventy-five  per  cent  of  water ;  in  this  condition 
they  are  somewhat  richer  in  the  food  compounds  than 
green  fodders,  and  are  an  excellent  feed.  They  are,  how- 
ever, liable  to  ferment  rapidly,  especially  in  warm  weather, 
which  causes  serious  loss,  besides  making  them  unfit  for 
food.  The  grains,  when  dried  before  fermentation  sets 
in,  make  a  wholesome  and  highly  concentrated  food, 
richer  in  both  fat  and  protein  than  bran  or  middlings, 
and  because  of  their  high  food  value  and  bulk  are  an 
excellent  substitute  for  oats.  Malt  sprouts  are  also  rich 
in  protein,  though  poorer  in  fat  than  the  dried  grains. 

Gluten  Feeds.  —  Gluten  feeds  occur  as  residues  in 
the  manufacture  of  either  starch  or  glucose  (grape  sugar) 
from  maize  or  Indian  corn,  and  consist  of  a  series  of 
products,  which,  when  dried,  are  classed  as  gluten  feed, 
gluten  meal,  germ  meal,  and  corn  bran.  Gluten  feed 
consists  of  the  entire  residue;  it  is  quite  bulky,  and 
much  richer  in  fat  and  protein  than  the  original  corn. 
In  gluten  meal  the  hull  or  germ  of  the  corn  has  been 
removed,  thus  largely  increasing  the  content  of  both  fat 
and  protein.  It  is  one  of  the  most  concentrated  of  the 
nitrogenous  feeds,  and  should  be  used  with  great  care. 
The  germ  meal  contains  a  large  proportion  of  the  germ 
of  the  corn.  It  contains  more  fat  and  less  carbohydrates 
than  corn,  and  about  the  same  amount  of  protein.  Corn 
bran  usually  consists  of  a  mixture  of  the  germ  and  hulls 
of  the  corn.  It  contains  about  the  same  amount  of  fat 
and  protein  as  corn,  with  less  carbohydrates  and  more 
fibre.  It  is  more  bulky  than  the  others.  Germ  meal 
and   corn   bran    serve    as   excellent  substitutes  for  corn 


152         FIRST  PRINCIPLES  OF  AGRICULTURE. 

meal.  Brewers'  grains  and  all  of  the  gluten  products 
contain  much  less  ash  than  the  original  barley  or  corn, 
the  soluble  salts  being  extracted  in  the  process  of  manu- 
facture. 

Hominy  Meal.  —  Hominy  meal,  a  residue  in  the  manu- 
facture of  hominy,  consists  chiefly  of  the  germ  and  hull 
of  the  corn,  and  corresponds  in  composition  with  the 
germ  meal,  though  much  richer  in  ash. 

Cottonseed  Meal.  —  Cottonseed  meal  is  derived  in 
the  manufacture  of  cottonseed  oil  from  the  cottonseed. 
This  feed  is  of  two  kinds :  one  in  which  the  hulls  of  the 
seed  have  been  removed,  in  which  case  it  is  called  "  de- 
corticated ; "  the  other  called  "  undecorticated,"  in  which 
the  hulls  have  not  been  removed.  Both  are  rich  in  pro- 
tein and  fat ;  though  the  former  is  far  superior  as  a  food, 
both  because  of  its  higher  content  of  nutrients,  and  its 
greater  palatability  and  digestibility.  The  concentration 
and  nitrogenous  character  of  these  feeds  make  them 
very  valuable,  particularly  when  fed  in  connection  with 
coarse  products,  though  because  of  their  concentration 
they  should  be  used  with  great  care. 

Linseed  Meal.  —  This  product,  sometimes  called  oil 
meal,  is  a  residue  from  the  manufacture  of  oil  from  flax- 
seed, and  is  of  two  kinds,  called  "  old  process  "  and  "  new 
process ; "  the  former  derived  when  the  fat  is  extracted 
by  pressure,  the  other  when  solvents  are  used.  There 
is  but  little  difference  in  their  feeding  value,  the  larger 
amount  of  fat  in  the  "old  process"  being  balanced  by 
an  increased  amount  of  protein  in  the  "new  process." 
Both  are  rich  in  protein,  and  show  a  high  rate  of  di- 
gestibility. 


GROWTH  OF  ANIMALS  ;    ANIMAL  FOOD.         153 

Eice  Bran,  Peanut  Meal.  —  These  are  also  excellent 
feeds,  though  not  so  generally  distributed.  It  should  be 
remembered,  however,  that  all  these  mentioned,  and  a 
number  of  minor  importance,  are  valuable  for  their  con- 
tent of  fat,  protein,  and  carbohydrates;  that  many  of 
them  represent  the  more  valuable  parts  of  grains ;  that 
they  are  quite  as  much  feeds  as  if  existing  in  their 
original  natural  condition,  and  should  find  a  place  on  all 
well-managed  farms. 


154  FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER   XIII. 

The  Digestibility  of  Fodders  and  Feeds ;  Feeding  Standards ; 
Nutritive  Ratio ;  The  Exchange  of  Farm  Products  for  Con- 
centrated Feeds. 

The  nourishment  that  may  be  derived  from  any  food 
depends  not  only  upon  its  composition  in  reference  to 
the  specific  food  substances  that  it  contains,  but  also 
upon  the  amount  of  these  that  may  be  digested  by  the 
animal. 

Digestibility  of  Fodders  and  Feeds.  —  Pure  nu- 
trients, as  albumen,  starch,  or  fat,  are  regarded  as 
entirely  digestible.  These  nutrients,  however,  do  not 
exist  in  the  various  feeding  materials  in  a  pure  state. 
They  are  associated  with  substances  that  are  indigesti- 
ble, or  that  hinder  their  digestibility;  hence  the  entire 
digestibility  of  a  food  is  governed  both  by  the  purity 
of  the  nutrients  which  it  contains,  and  by  the  ab- 
sence of  those  compounds  which  prevent  the  complete 
action  of  the  digestive  fluids. 

Seeds  of  plants,  as  a  rule,  contain  matter  of  a  readily 
digestible  character ;  that  is,  the  nutrients  contained  in 
them  are  relatively  pure :  but  they  are,  in  many  cases, 
enclosed  in  a  hard  shell,  and,  particularly  if  swallowed 
whole,  resist  the  action  of  the  digestive  processes,  thus 
preventing    the   digestion    of    the    entire   seed.      In  the 


FODDERS  AND  FEEDS.  155 

same  manner  the  nutrients  in  such  products  as  hay  and 
straw  frequently  pass  through  the  animal  undigested, 
because  they  are  surrounded  by  the  woody  and  almost 
impervious  fibre  of  the  cell  wall,  which  prevents  the 
attack  of  the  digestive  fluids. 

Fodders,  therefore,  on  account  of  the.  great  proportion 
of  fibre  they  contain,  are  less  digestible  than  the  finely 
ground  concentrated  feeds.  The  cutting  and  crushing 
of  the  coarse  fodders,  and  the  fine  grinding  of  the  vari- 
ous grains  and  seeds,  favorably  influence  the  rate  of 
digestibility.  The  digestibility  of  a  fodder  or  a  feed 
is  also  influenced  by  other  conditions,  such  as  the  pro- 
portion of  the  three  classes  of  food  constituents  con- 
tained in  it ;  the  period  of  growth  at  time  of  harvesting 
the  forage ;  methods  of  curing  and  storage ;  the  kind 
or  breed  of  animal  to  which  it  is  fed ;  the  age  of  the 
animal,  its  individual  peculiarities;  and  many  other  in- 
fluences of  a  minor  character,  all  of  which  should  be 
regarded  in  the  preparation  of  rations. 

The  Digestion  Co-efficients;  Their  Derivation  and 
Use.  —  The  relative  digestibility  of  the  different  prod- 
ucts for  various  purposes  under  ordinary  conditions  of 
feeding,  have  been  determined  by  actual  feeding  experi- 
ments. Such  experiments  have  been  conducted  both 
here  and  in  Europe,  and  the  data  derived  from  a  large 
number  are  of  great  service  in  determining  the  com- 
parative value  of  the  different  feeds.  In  these  experi- 
ments, the  food  and  manure  are  weighed,  and  the 
analyses  made ;  and  the  difference  between  the  total 
amount  of  the  constituents  in  the  food  and  in  the 
dung    shows    how    much    of    each    has    been     digested ; 


156         FIRST  PRINCIPLES  OF  AGRICULTURE. 

the  amount  or  the  per  cent  digested  is  called  "the  di- 
gestion co-efficient." 

For  example,  it  is  found  by  experiments  that  clover 
hay  of  average  quality  shows  digestible :  — 

Fat 43  per  cent. 

Fibre 48      " 

Protein 49      " 

Nitrogen-free  extract 58      " 

These  figures  represent  the  proportion  or  pounds  per 
hundred  of  the  various  constituents  digested,  and  are  used 
in  calculating  the  digestibility  of  other  samples  of  the 
same  kind  of  product  of  average  quality.  They  are  the 
digestion  co-efficients. 

The  average  composition  of  clover  hay  is  :  — 

Water 15.3  per  cent. 

Crude  Fat 3.3      " 

Crude  Fibre 24.8      " 

Crude  Protein 12.3       " 

Crude  Ash 6.2      " 

Nitrogen-free  extract 38.1       " 

The  calculation  of  the  digestibility  of  clover  hay  is, 
therefore,  as  follows  :  — 

Digestible  Fat 3.3x0.43=   1.42  per  cent. 

Digestible  Fibre 24.8x0.48  =  11.90       " 

Digestible  Protein 12.3x0.49=  6.03       " 

Nitrogen-free  extract    ....  38.1x0.58  =  22.10       " 

The  digestible  fibre  has  been  found  to  consist  of  cel- 
lulose ;  hence,  in  stating  the  digestibility  of  a  food,  the 
per  cent  of  crude  fibre  digested  is  added  to  the  nitrogen- 
free  extract,  and  the  result  stated  as  follows  :  — 

Fat       1.42  per  cent. 

Protein 6.03       " 

Carbohydrates 34.00      " 


FODDERS  AND  FEEDS.  157 

The  Objects  of  Feeding.  —  The  objects  for  which 
we  feed  are :  1.  Simply  to  maintain  life ;  that  is,  to 
replace  by  food  the  natural  wastes  of  the  body  conse- 
quent upon  the  simple  exercise  of  the  vital  functions, 
as  described  in  the  previous  chapter;  and  2.  To  main- 
tain life,  and  at  the  same  time  to  increase  animal  prod- 
uct or  work.  It  is  in  carrying  out  the  second  object 
that  skill  and  knowledge  are  required,  in  order  that 
the  use  of  the  food  may  result  in  the  greatest  and  most 
economical  production. 

Animal  Products  Differ  in  Their  Character  and 
Composition.  — The  different  results  accomplished  by 
feeding,  as  maintenance  of  life,  the  production  of  milk, 
flesh,  fat,  wool,  etc.,  are  not  only  different  in  their  char- 
acter, but  in  order  to  secure  them  at  the  least  outlay  of 
actual  nutrients,  different  proportions  of  the  digestible 
compounds  contained  in  feeds  must  be  provided. 

In  the  simple  maintenance  of  life,  where  there  is  no 
gain  in  flesh,  the  chief  nutrients  required  are  those 
which  best  supply  the  heat  and  energy  necessary  to 
maintain  the  vital  processes ;  viz.,  non-nitrogenous  sub- 
stances :  hence  it  is  that  hay,  straw,  and  stalks,  which 
possess  the  requisite  bulk,  and  are  rich  in  this  class  of 
substances,  serve  an  excellent  purpose  in  the  prepara- 
tion of  maintenance  rations  for  cattle  and  horses. 

To  secure  a  product  rich  in  protein,  as  milk  or  flesh, 
the  feeds  must  contain  a  greater  proportion  of  protein 
than  is  necessary  when  the  object  of  feeding  is  fat, 
since  the  digestible  protein  of  the  food  is  the  sole  source 
of  the  protein  in  the  body ;  while  all  the  nutrients  may 
contribute  to  the  formation  of  the  fat.     In  a  young  ani- 


158         FIBST  PRINCIPLES   OF  AGRICULTURE. 

mal,  too,  a  large  portion  of  the  nutriment  is  used  in 
making  muscle,  tissue,  and  bone;  while  in  a  mature  ani- 
mal the  amount  of  the  food  constituents  that  go  to  form 
new  products  is  comparatively  small,  the  larger  portion 
being  used  in  maintaining  animal  heat. 

The  proportion  of  the  three  general  classes  of  -ood 
compounds  should  therefore  be  different  for  the  various 
purposes  of  feeding. 

The  Proportion  of  the  Pood  Constituents  Re- 
quired for  the  Different  Purposes  of  Feeding.  — 
Experiments  in  feeding  animals  have  been  conducted 
in  which  all  variable  conditions  have  as  far  as  possible 
been  controlled,  in  order  to  secure  exact  data  as  to  the 
proper  proportions  in  a  ration,  as  well  as  the  amounts  of 
the  nitrogenous  and  non-nitrogenous  substances  required 
for  the  various  purposes  of  feeding.  The  results  of  these 
experiments  have  led  to  the  fixing  of  what  are  termed 
"  feeding  standards  ; "  that  is,  statements  of  the  amounts 
of  digestible  protein,  or  albuminoids,  fat  and  carbohy- 
drates, which  appear  to  be,  and  are  perhaps  under  aver- 
age conditions,  best  adapted  to  the  various  conditions  of 
the  animal  and  the  numerous  purposes  of  feeding. 

Feeding  Standards.  —  The  "  feeding  standards  "  in 
most  common  use  are  those  of  the  German  experimenter 
Wolff,  which  are  given  in  the  Appendix.  For  example, 
his  standard  ration  per  day  for  a  milch  cow  of  one  thou- 
sand pounds  live  weight,  in  full  flow,  requires  twenty-five 
pounds  of  organic  substance,  which  shall  contain  0.40 
(i.e.,  four-tenths)  pounds  of  digestible  fat,  2.50  pounds  of 
digestible  protein,  and  12.50  pounds  of  digestible  car- 
bohydrates.     A   ration    for    dairy   cows    showing    these 


FODDERS  AND  FEED.  159 

amounts  and  proportions,  or,  in  fact,  any  ration  conform- 
ing to  the  required  "  standard,"  is  also  called  a  "  balanced 
ration,"  and  one  showing  other  proportions  is  called  "  un- 
balanced." These  expressions  are  used  to  indicate  that 
the  proportions  in  the  "  balanced  ration "  are  such  as  to 
insure  the  best  use  by  the  animal  of  all  the  food  constit- 
uents contained  in  it ;  while  in  the  "  unbalanced  ration  " 
the  proportions  are  such  as  to  indicate  a  waste  of  one  or 
the  other  classes  of  food  compounds,  because  contained 
in  quantities  exceeding  the  needs  of  the  animal.  For 
instance,  if  a  milch  cow  is  fed  a  ration  higher  in  car- 
bohydrates, and  lower  in  protein,  than  is  indicated  by 
the  standard,  she  will,  of  necessity,  in  order  to  secure 
the  requisite  protein,  consume  more  carbohydrates  than  the 
system  requires,  thus  entailing  a  waste  of  this  sub- 
stance. 

The  Usefulness  of  Feeding  Standards.  —  It  is  evi- 
dent that  the  amounts  and  proportions  of  digestible  food 
compounds  given  by  the  standard  are  not  the  best  for 
every  cow  under  all  conditions  of  full  milk  flow ;  for  dif- 
ferent cows  differ  not  only  in  their  capacity  to  utilize 
food,  but  also  in  the  amount  of  milk  produced  when  in 
full  flow.  The  same  holds  true  of  standards  for  other 
animals;  that  which  is  the  best  for  one  may  not  be  the 
best  for  another. 

Feeding  standards  are,  therefore,  mainly  useful  as 
guides  in  the  selection  of  food  products  for  the  prepara- 
tion of  rations ;  and,  though  they  should  not  be  regarded 
as  positive  rules,  the  experiments  conducted  in  connec- 
tion with  the  experience  of  practical  feeders  indicate 
that  the   amount   and   proportion   of  the   digestible   food 


160        FIRST  PRINCIPLES  OF  AGRICULTURE. 

compounds  given  by  the  standard  can  be  followed  with 
great  advantage.  In  many  cases,  too,  while  the  propor- 
tions given  by  the  standards  would  furnish  the  greatest 
return  for  the  amount  fed,  other  proportions,  because 
of  the  prices  of  feed,  may  give  the  largest  money  re- 
turns to  the  feeder.  The  use  of  feeding  standards  must 
be  accompanied  with  judgment  on  the  part  of  the  feeder 
regarding  the  individuality  of  the  animal,  and  the  char- 
acter of  feeds  and  their  cost,  as  well  as  the  object  of 
feeding.  That  is,  animals  must  be  fed  as  individuals, 
with  peculiarities  of  appetite,  digestion,  and  assimila- 
tion, not  as  fixed  machines. 

Nutritive  Ratio.  —  In  a  ration  for  simple  mainte- 
nance, the  proportion  of  the  fats  and  carbohydrates  to- 
gether may  be  greatly  in  excess  of  the  digestible 
protein;  while  for  the  production  of  milk,  or  of  flesh 
products  which  are  rich  in  albumen  and  casein,  the 
direct  and  only  source  of  these  compounds,  viz.,  digest- 
ible protein,  should  be  proportionately  increased.  The 
proportion  of  the  one  class  of  substances  to  the  other 
is  called  "nutritive  ratio,"  and  is  obtained  as  fol- 
lows :  — 

The  sum  of  the  digestible  carbohydrates  and  two  and 
one-fourth  times  the  digestible  fat  is  divided  by  the 
digestible  protein  in  the  ration ;  the  quotient  gives  the 
nutritive  ratio.  The  calculation  of  the  nutritive  ratio 
of  clover  hay,  from  the  analysis  and  digestibility  given 
on  page  156,  will  serve  as  an  example  of  the  method:  — 

Digestible  Fat,  X  2J =    3.19 

Digestible  Carbohydrates =  34.00 

37.19 
Digestible  Protein 6.03 


FODDERS  AND  FEEDS.  161 

The  nutritive  ratio  is  6.03  to  37.19,  or  1  to  6.2 ;  that 
is,  one  part  of  digestible  nitrogenous  substances,  some- 
times called  "flesh  formers,"  to  6.2  parts  of  digestible 
non-nitrogenous  matter,  or  "  fat  formers." 

"Wide  vs.  Narrow  Rations. — If  the  quantities  of 
digestible  fat  and  carbohydrates  are  large  relatively  to 
the  protein,  this  number  will  be  large,  and  the  ration  is 
called  a  "  wide  ration."  If  the  quantities  of  digestible 
fat  and  carbohydrates  are  relatively  small,  the  quotient 
is  a  small  number,  and  the  ration  is  a  "  narrow "  one. 
A  ration  where  the  nutritive  ratio  is  much  more  than 
1  to  6  may  be  called  a  "  wide  ration,"  if  much  less  it  may 
be  called  a  "  narrow  ration." 

Very  few  natural  feeds  conform  closely  to  the  stan- 
dards given  for  the  various  purposes  of  feeding.  Coarse 
farm  products  show  a  very  wide  nutritive  ratio,  and 
are  only  well  adapted  for  maintenance ;  while  many  of 
the  concentrated  feeds  show  a  much  narrower  nutritive 
ratio  than  is  called  for  by  the  standards,  even  for  the 
production  of  milk  or  flesh.  This  makes  it  necessary,  in 
order  to  economically  use  food  products,  to  combine  those 
rich  in  carbohydrates,  or  possessing  a  wide  nutritive 
ratio,  with  those  rich  in  protein,  and  possessing  a  nar- 
row ratio. 

The  Preparation  of  Rations. — The  preparation  of 
rations  requires,  however,  more  than  a  simple  combina- 
tion of  nitrogenous  and  non-nitrogenous  foods  in  such  a 
manner  as  to  secure  the  proper  nutritive  ratio.  The 
bulk  of  the  ration,  as  well  as  the  palatability  and  digest- 
ibility must  be  regarded ;  there  must  be  sufficient  bulk 
to  properly  distend  the  stomach;   food  too  concentrated 


162        FIRST  PRINCIPLES  OF  AGRICULTURE. 

in  character,  though  supplying  the  requisite  nutrients, 
causes  an  uneasy  and  unsatisfied  feeling,  and  it  is  evi- 
dent that  bulk  should  be  different  for  the  cow  than  for 
the  horse  or  pig.  For  milch  cows  it  may  consist,  in 
large  measure,  of  straw,  which  is  partially  digestible, 
and  usually  palatable;  while  for  the  horse  or  pig  an 
abundance  of  straw  would  serve  a  less  useful  purpose, 
because  of  the  smaller  size  and  different  formation  of 
the  stomach,  and  because  in  the  latter  the  food  is  not 
re-masticated,  as  is  the  case  with  the  cow. 

Palatability  is  also  an  important  feature,  since  the 
amount  of  animal  product  secured  is  largely  dependent 
upon  the  amount  of  food  the  animal  can  be  made  to 
consume  over  an^  above  that  necessary  to  maintain  life. 
Too  much  indigestible  matter  must  also  be  avoided ;  since 
it  is  liable  to  disarrange  the  system,  because  of  the 
extra  work  required  to  properly  dispose  of  it. 

To  insure  the  minimum  waste  of  nutritious  matter, 
such  coarse  products  as  corn-stalks  and  straw,  which  in 
their  original  state  are  not  readily  and  completely  eaten 
by  animals,  musx  be  cut,  the  coarser  and  finer  portions 
intimately  mixed,  and  feeds  of  known  relish  added. 

The  following  examples  show  how  various  fodders  and 
feeds  may  be  combined  in  order  to  secure  such  propor- 
tions of  the  digestible  food  compounds  as  experiments 
and  experience  have  taught  us  are  well  adapted  to  the 
purposes  indicated,  while  at  the  same  time  possessing 
the  features  discussed  in  reference  to  bulk  and  palata- 
bility. The  tables  in  the  Appendix  furnish  the  data 
necessary  for  the  calculation  of  digestibility  and  nutri- 
tive ratio :  — 


FODDERS  AND  FEEDS. 


163 


Daily  Ration*  Based  Upon    1,000  lbs.  Live  "Weight. 


Fob  Growing  Cattle, 
6-12  months'  old. 


1. 


2. 


15  pounds  Corn  Stalks. 
10      "       Wheat  Bran. 
3      "        Linseed  Meal. 


20  pounds  Clover  Hay. 
6       "        Corn  Meal. 
2      "       Linseed  Meal. 


For  Fattening  Stock. 


1. 


2. 


10  pounds  Timothy  Hay. 
8      "        Oat  Straw. 

5  "        Corn  Meal. 

6  "        Wheat  Bran. 

3      "       Cottonseed  Meal. 


10  pounds  Corn  Stalks. 
6       "        Wheat  Straw. 
6       "        Wheat  Middlings. 
3       "        Linseed  Meal. 
5      "       Corn  Meal. 


For  Milch  Cows. 


1. 


2. 


5  pounds  Timothy  Hay. 


10  pounds  Mixed  Hay. 


5  " 

6  " 
6       " 
2       " 
8      " 

Shredded  Corn  Stalks. 
Corn  and  Oat  Meal. 
Wheat  Bran. 
Cottonseed  Meal. 
Roots. 

4 
4 
3 
2 
1 

1        Corn  Meal. 
'        Malt  Sprouts. 
'        Wheat  Bran. 
'        Linseed  Meal. 
'        Cottonseed  Meal 

Horses  for  Farm  Wore. 

Hors 

E8  for  Road  Work. 

12  pou  ml 

6      " 

4      " 
1       " 

\  Timothy  Hay. 
Corn. 
Oats. 
Linseed  Meal. 

10  pou 
10       ' 

6       ' 
2 

nds  Timothy  Hay. 
'        Oats. 
'        Wheat  Bran. 
'        Linseed  Meal. 

These  rations,  however,  are  intended  to  show  chiefly 
good  proportions  of  the  various  materials ;  the  amounts 
should  be  adjusted  by  the  feeder  to  best  meet  the  require- 
ments of  the  individual  animal.  Care  in  respect  to  feed- 
ing is  quite  as  important  as  the  selection  of  the  various 
products.  The  amount  and  kind  of  concentrated  feed 
are  also  matters  of  importance.  The  highly  nitrogenous 
cottonseed,  linseed,  and  gluten  meals  must  be  fed  in 
small  amounts,  ranging  from  two  to  four  pounds  per  day 


164        FIRST  PRINCIPLES  OF  AGRICULTURE. 

for  milch  cows;  while  bran,  dried  brewers'  grains,  and 
corn  meal,  can  be  safely  fed  in  larger  quantities.  It  is 
desirable,  when  possible,  to  make  the  ration  consist  of 
a  small  quantity  each  of  a  number  of  feeds,  rather  than  a 
larger  quantity  of  one  or  two ;  since  it  usually  adds  to  the 
palatability,  lessens  the  danger  of  overfeeding,  and  per- 
mits a  frequent  change  of  diet. 

Practical  Methods  of  Using  Balanced  Rations.  — 
Where  the  appliances  for  making  weights  at  each  feed 
are  not  at  hand,  and  it  is  preferable  to  measure,  the  dif- 
ferent materials  should  be  weighed  at  least  once,  and 
the  relation  between  a  certain  weight  and  a  certain  bulk 
ascertained.  The  weight  or  measure  of  feed  for  a  day's 
ration  for  a  herd  may  be  mixed  together  in  the  propor- 
tions given,  and  in  feeding  they  should  be  distributed 
in  such  a  way  as  to  give  animals  of  different  weights 
and  capacities  for  using  food  that  amount  best  adapted 
for  them.  In  feeding  dairy  animals,  where  there  are  a 
number  of  dry  cows,  the  mixtures  for  each  lot  would 
better  be  made  separately.  For  horses,  the  grain  or  feed 
rations  for  work  and  maintenance  may  each  be  mixed  in 
considerable  quantities,  and  placed  in  separate  bins. 

Exchange  of  Farm  Products  For  Concentrated 
Feeds.  —  A  comparison  of  the  nutritive  ratio  of  the 
various  natural  farm  products,  —  hay,  grain,  straw,  and 
corn  stalks  or  fodder  —  and  of  the  various  feeding  stand- 
ards, as  already  indicated,  shows  that,  with  few  excep- 
tions aside  from  the  maintenance  ration,  these  contain 
a  decided  excess  of  carbohydrates,  or,  in  other  words, 
the  nutritive  ratio  of  the  various  farm  products  is  too 
wide  when  the  purpose  of  feeding  is  increase  in  animal 


FODDERS  AND  FEEDS.  165 

product.  This  is  even  more  striking  if  only  the  coarse 
products  —  hay,  straw,  stalks,  and  corn  —  are  retained  by 
the  farmer  for  his  purposes ;  hence,  in  the  purchase  of 
feeds  that  shall  balance  rations  made  from  home-grown 
produce,  those  should  be  selected  which  show  a  narrow 
nutritive  ration  or  an  excess  of  protein. 

Actual  Practice  is  Often  "Wasteful.  —  In  too  many 
cases  in  actual  practice,  in  order  to  enrich  the  ration 
fed,  constituents  are  added  that  are  already  in  excess ; 
and  hence,  while  an  increase  in  result  may  be  obtained, 
there  is  also  an  increased  waste  of  valuable  constituents. 
To  add  corn  meal,  an  excellent  food  product,  to  corn 
fodder  or  corn  stalks,  —  that  is,  carbohydrates  to  carbo- 
hydrates, —  in  the  preparation  of  rations  for  dairy  cows, 
may  increase  the  product  of  the  dairy,  but  it  is  by 
virtue  of  an  increased  total  consumption  of  food,  because 
of  the  more  concentrated  character  of  the  ration,  rather 
than  by  an  economical  use  of  the  constituents.  A  waste 
of  food  is  only  warranted  when  it  is  cheaper  to  waste 
than  to  utilize. 

Economy  in  Selling  Grain  and  Buying  Feed.  —  In 
many  cases,  too,  the  cost  of  the  nutrients  in  the  com- 
mercial concentrated  feeds  is  much  less  than  is  secured 
by  the  farmer  for  the  same  nutrients  in  whole  grains ; 
under  such  circumstances,  to  sell  the  larger  part  of  his 
grain  and  hay  crops,  and  to  purchase  in  return  those 
feeds  which  will  enable  him  to  utilize  his  coarse  prod- 
ucts, like  straw  and  corn  stalks,  to  the  best  advantage, 
is  a  desirable  practice.  It  must  be  remembered  that  the 
waste  or  refuse  feed  products  usually  consist  of  parts 
of  grain,  and  hence,  so  far  as  nutrients  go,  are  quite 
as  serviceable  as  the  original  products. 


166        FIRST  PRINCIPLES   OF  AGRICULTURE. 

Fertility  in  Feeds A  fodder  or  feed  has  a  fertiliz- 
ing value  by  virtue  of  the  manurial  constituents  —  nitro- 
gen, phosphoric  acid,  and  potash  —  contained  in  it.  Corn, 
oats,  hay,  wheat,  or  other  crops,  when  sold  from  the 
farm,  carry  with  them  a  certain  portion  of  these  con- 
stituents ;  and  the  sale  of  these  products  continued  for  a 
long  time  must  result  in  the  exhaustion  of  the  soil.  If 
they  are  returned  to  the  land  in  whole  or  in  part,  they 
will  aid  in  the  growth  of  other  plants,  and  the  time  of 
exhaustion  is  postponed. 

The  Relative  Fertility  of  Fodders  and  Feeds. — 
Fodders  are  much  less  valuable  as  direct  manures  than 
the  feeds,  —  first,  because  they  contain  less  of  the  essential 
constituents ;  and  second,  because,  from  their  woody  char- 
acter, their  decay  is  less  rapid,  though  both  are  valuable 
as  indirect  manures,  because  of  their  high  content  of  or- 
ganic vegetable  matter.  The  direct  fertilizing  value  of  a 
feed  is  largely  measured  by  its  content  of  nitrogen ;  though 
the  ash  constituents,  phosphoric  acid  and  potash,  are  also 
of  considerable  importance. 

Mill-Feeds  vs.  Commercial  Fertilizers.  —  Fine- 
ground  mill-feeds,  though  less  concentrated,  are  quite 
as  good  sources  of  available  organic  nitrogen  as  the  best 
commercial  forms  furnishing  that  element ;  the  phosphoric 
acid  is  less  valuable  than  when  contained  in  forms  com- 
pletely soluble  in  water,  because  decay  must  take  place 
before  it  becomes  available  to  the  plant ;  while  the  potash, 
which  is  largely  soluble  in  water,  is  regarded  as  equiva- 
lent in  value  to  that  contained  in  forms  free  from  muri- 
ates. Of  all  the  feeds  we  have,  cottonseed  meal  is  the 
richest  in  fertilizing  constituents.     In  the  Southern  States 


FODDERS  AND  FEEDS.  167 

it  is  used  directly  as  a  manure,  and  even  in  the  Northern 
States  it  is  one  of  the  cheapest  sources  of  organic  nitro- 
gen. Linseed  meal,  malt  sprouts,  dried  brewers'  grains, 
and  a  number  of  others,  are  much  richer  in  nitrogen  than 
the  average  commercial  fertilizer,  though  their  higher  rela- 
tive cost  forbids  their  direct  use  as  nitrogenous  manures. 

Refuse  Feeds  are  Rich  in  Fertility.  —  Feeds,  there- 
fore, in  addition  to  their  food  value,  possess  an  actual  and 
sometimes  a  considerable  value  as  a  fertilizer.  This  point 
should  be  carefully  regarded  in  their  purchase,  and  espe- 
cially as  bearing  upon  the  point  already  emphasized  :  viz., 
the  exchange  of  home-grown  produce  for  them ;  for  it  is 
an  important  fact  that  the  crops  grown  which  contain  the 
highest  amount  of  carbohydrates,  and  thus  in  many  cases 
the  most  desirable  to  dispose  of  from  the  standpoint  of 
economical  feeding,  are  those  which  contain  the  smallest 
amounts  of  the  fertilizing  constituents ;  while  those  com- 
mercial feeds  containing  protein  in  large  amounts  —  the 
substance  usually  deficient  in  home-grown  produce  —  are 
rich  in  nitrogen,  and  often  richer  also  in  ash  constituents. 
Hence  it  is  that  on  farms  where  stock  is  kept,  a  judicious 
exchange  of  farm  products  for  concentrated  feeds  may 
result  in  soil  improvement,  rather  than  soil  exhaustion, 
even  with  the  continuous  sale  of  crops.  It  is  a  fact,  too 
that  the  prices  of  feeds,  as  well  as  the  crops  sold,  are 
governed  entirely  by  market  conditions ;  that  is,  no  ac- 
count is  made  of  the  fertility  value,  hence  the  fertilizer 
constituents  gained  by  this  exchange  are  a  clear  gain  to 
the  farmer. 

A  good  example  of  the  advantages  of  a  careful  obser- 
vation of  these  points  is  shown  by  a  comparison  of  corn 


168        FIRST  PRINCIPLES  OF  AGRICULTURE. 

meal  and  wheat  middlings,  valuable  food  products,  which 

contain  practically  equivalent  amounts  of  total  digestible 

food,    and  which  usually  cost  about  the  same  price  per 

ton :  — 

Pounds  or 
Nitrogen.    Phosphoric  Acid.    Potash. 
One  ton  of  Corn  Meal  contains      ...    33  14  8 

One  ton  of  Wheat  Middlings  contains  .50  28  14 

Excess  in  Middlings 17  14  6 

That  is,  by  the  exchange  of  one  ton  of  corn  meal  for  one 
ton  of  wheat  middlings,  there  is  not  only  no  loss  of  fertil- 
ity, but  a  gain  in  mineral  constituents  nearly  equivalent 
to  that  contained  in  one  ton  of  the  corn  meal.  The  use  of 
tables  in  the  Appendix  will  enable  the  student  to  make 
correct  comparisons  of  the  fertility  values  of  the  chief 
farm  crops  and  purchased  feeds. 

Manurial  Value.  —  The  direct  fertilizing  value  of  a 
ton  of  feed  is,  however,  greater  than  the  manurial  value  of 
the  same;  since,  in  feeding,  a  portion  of  the  fertilizing 
constituents  is  retained  in  the  animal  itself  or  obtained 
in  animal  product,  the  amount  depending  upon  the  kind 
of  animal,  and  the  object  of  feeding. 

The  quantity  of  nitrogen  and  ash  constituents  voided  in 
the  manure  of  a  grown  animal,  neither  gaining  nor  losing 
in  weight,  will  be  nearly  the  same  as  that  contained  in 
the  food  consumed.  In  case  animals  are  increasing  in  size, 
producing  young,  or  furnishing  milk  or  wool,  the  nitrogen 
and  ash  constituents  in  the  manure  will  be  less  than  in  the 
food,  in  direct  proportion  to  the  quantity  of  these  sub- 
stances which  have  been  converted  into  animal  products. 

The  data  secured  in  experiments  by  Lawes  &  Gilbert, 
at  Eothamsted,  England,  contained  in  the  following  table, 


FODDERS  AND  FEEDS. 


169 


are  perhaps  fairly  representative  of  the  amounts  of  fer- 
tilizer constituents  retained  from  the  feeds  in  the  various 
animal  products :  — 


Percent agk 

Percentage 

OF  NlTEOG 

of  Ash 

Constituents. 

"3  • 

2 

•a 
•g 

4 

£i 

*i 

o  . 

V.  - 

tfj 

H 

ss 

o  ■ 

S-d 

s 

35 

w 

I.   b 
cs  0 

Hfi 

—  u 

*s 

SB 

rt 

"3  a 

S  o    • 

vfri 

«£ 

«i 

*  *i 

AN 

■8*0 

4)  » 

»  « 

o  a 

IS  -   - 

<  2 

•O  M 

•0  M 

^  S 

I! 

■c  g-g 

sa 

o« 

"S« 

aS 

Ofl>i 

o 

> 

> 

O 

> 

Horse  at  Rest 

None 

43.0 

67.0 

100.0 

None 

100.0 

Horse  at  Work       .... 

None 

29.4 

70.6 

100.0 

None 

100.0 

Fattening  Oxen     .... 

3.9 

22.6 

73.5 

96.1 

2.3 

97.7 

Fattening  Sheep    .... 

4.3 

16.7 

79.0 

95.7 

3.8 

96.2 

Fattening  Pigs 

14.7 

22.0 

63.3 

85.2 

4.0 

96.0 

Milking  Cows 

24.5 

18.1 

57.4 

75.5 

10.3 

89.7 

Manurial  Constituents  should  be  saved.  —  The 
amount  of  fertilizer  constituents  voided  in  the  manure 
may,  however,  be  greater  than  the  amount  actually  pres- 
ent when  the  manure  is  used,  because  of  the  losses  that 
may  occur  between  the  time  it  is  produced  and  the  time 
it  is  applied  to  the  land ;  hence  the  precautions  given 
in  a  previous  chapter  concerning  the  care  and  manage- 
ment of  manures  should  be  carefully  followed. 


170         FIRST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER  XIV. 
Principles  of  Breeding ;  The  Pure  Breeds  of  Farm  Stock. 

The  various  breeds  of  horses,  cattle,  sheep,  and  swine, 
are  the  result  in  large  measure  of  attempts  to  secure  the 
best.  A  single  breed  of  cattle,  for  instance,  could  not  meet 
in  the  best  manner  all  the  requirements  that  the  numerous 
conditions  now  demand.  We  must  have  animals  adapted 
for  a  definite  specific  production,  rather  than  for  general 
purposes ;  viz.,  work,  speed,  endurance,  butter,  milk,  meat, 
wool,  and  fat.  A  distinct  breed  is  one  which  possesses 
distinct  characteristics  of  color,  form,  and  habit,  which 
are  transmitted  without  material  change  to  the  offspring. 
The  best  breed  is  that  which  best  meets  the  demands 
in  any  specific  case. 

Principles  of  Breeding Breeding  is  an  art  rather 

than  an  exact  science,  though  it  is  scientific  in  that  it 
is  based  upon  scientific  principles  or  natural  laws.  These 
must  be  observed  in  order  both  to  attain  and  to  retain 
the  specific  characteristics  desired. 

Heredity,  or  the  law  that  "like  begets  like,"  is  the 
most  important.  It  is  regarded  as  the  corner-stone  of  the 
art.  This  law  applies  not  only  to  outward  form,  but  also 
to  the  entire  characteristics;  animals  inherit  the  quali- 
ties, habits,  and  tendencies  of  their  parents,  both  good  and 
bad.     The  results  of  this  law  of  descent  are  observable 


PRINCIPLES  OF  BREEDING.  171 

on  all  sides,  both  in  the  lower  animals  and  in  man.  Cer- 
tain families  have  certain  peculiarities  or  habits,  good  or 
bad,  that  are  directly  traceable  to  their  ancestors ;  that 
is,  animals  bred  true  to  a  given  idea  or  type  for  a  long 
time  acquire  fixed  characters  or  peculiarities,  which  they 
are  capable  of  transmitting  unimpaired  to  their  offspring. 

The  law  of  heredity  is,  however,  only  true  in  a  general 
sense.  It  is  not  absolute ;  if  it  were,  the  improvement  of 
live  stock  would  be  impossible.  Certain  other  natural 
tendencies  are  constantly  active  to  modify  the  law  of 
heredity. 

Atavism,  or  Reversion,  is  the  name  given  to  qual- 
ities or  habits  in  the  offspring  which  were  not  possessed 
by  the  immediate  parents,  but  which  were  possessed  by 
some  remote  ancestor.  This  law  of  atavism,  or  tendency 
to  go  back  to  an  original  type,  is  familiar  to  all  breeders, 
and  frequently  causes  annoyance,  particularly  where  fine 
points  in  breeding  are  regarded  as  important.  Many  in- 
stances are  recorded  in  the  various  herd-books  of  the  ap- 
pearance of  calves  with  a  color  totally  different  from  that 
of  their  immediate  parents,  and  the  appearance  of  an  ani- 
mal with  horns  is  a  quite  common  occurrence  among  the 
recognized  hornless  breeds  of  cattle. 

Variation  is  a  tendency  in  the  offspring  to  be  un- 
like their  parents.  It  is  by  virtue  of  this  law  of  variation, 
which  is  readily  influenced  by  artificial  conditions,  that 
rapid  changes  in  types  may  be  effected  and  new  breeds 
formed. 

The  great  gain  in  maturity  and  meat-producing  qual- 
ities of  certain  breeds  of  cattle  is  due  in  a  great  measure 
to  better  methods  of  feeding,  in  connection  with  greater 


172         FIRST  PRINCIPLES  OF  AGRICULTURE. 

care  in  breeding.  This  influence  has  been  so  marked  as 
to  give  rise  to  the  common  expression  that  "feed  makes 
breed."  Habit  also  exercises  a  marked  influence  in  the 
development  of  valuable  characteristics,  a  striking  example 
of  which  is  observed  in  the  breeds  of  milch  cows.  The 
habit  of  giving  milk,  which  has  been  encouraged  for  a 
long  time,  has  caused  a  change  in  the  structure  and  func- 
tion of  the  animal.  In  the  early  breeds  the  tendency  to 
secrete  milk  was  not  a  prominent  characteristic;  it  was 
only  sufficiently  developed  to  satisfy  the  demands  of  the 
young. 

Prepotency,  or  the  superior  influence  of  one  parent  over 
the  other  in  determining  the  character  of  the  offspring, 
is  also  a  principle  which  exerts  a  decided  influence  in  the 
development  and  improvement  of  distinct  breeds.  Certain 
breeds,  as  well  as  certain  animals,  possess  this  characteristic 
in  a  marked  degree ;  that  is,  the  offspring  closely  resemble 
this  particular  breed  or  animal,  whatever  may  have  been 
the  character  of  the  other  parent.  Among  American  trot- 
ting-horses,  Eysdyk's  Hambletonian  showed  this  power  of 
individual  prepotency  in  a  remarkable  degree ;  his  get,  as 
a  rule,  not  only  resembling  him  in  color,  form,  gait,  temper, 
vigor,  and  endurance,  but  in  nearly  every  conceivable 
quality  that  he  possessed. 

Lineage.  —  Various  terms  are  used  to  express  the  birth 
and  descent  of  animals.  "  Pure-bred,"  "  thorough-bred,"  and 
sometimes  "  full-blood,"  are  terms  used  to  indicate  animals 
of  a  distinct  and  well-defined  breed.  "  Pure-bred  "  is  the 
only  strictly  correct  term ;  "  thorough-bred  "  is  the  name  of 
a  distinct  breed  of  English  race-horses,  while  "  full-blood  " 
hardly  expresses  the  idea. 


PRINCIPLES  OF  BREEDING.  173 

Cross-Bred  refers  to  animals  produced  by  breeding 
together  distinct  breeds;  for  example,  the  offspring  from 
the  breeding  together  of  pure-bred  Shorthorn  and  Jersey 
cattle,  or  of  pure-bred  Berkshire  and  Chester  white  swine, 
are  cross-breeds. 

Grades  are  the  product  of  a  cross  between  a  pure- 
bred and  a  native.  The  offspring  of  a  pure-bred  Jersey 
sire  and  a  cow  of  no  fixed  type  is  a  "  grade  "  Jersey ;  while 
a  "  high-grade  "  animal  is  one  in  which  the  blood  of  a  pure 
breed  is  in  excess.  The  offspring  of  a  "  pure-bred  "  Jersey 
and  a  "  grade  "  Jersey  is  a  "  high-grade." 

In-and-in  Breeding:  means  mating  animals  that  are 
closely  related  to  one  another.  This  method,  as  practised 
by  various  breeders,  differs  both  in  respect  to  the  degree 
of  relationship,  and  to  the  continuation  of  the  practice. 
Authorities  have  defined  the  term  as  applying  "  only  to 
animals  of  precisely  the  same  blood,  as  own  brother  and 
sister,"  and  also  as  "  pairing  of  relations  within  the  degree 
of  second  cousins  twice  or  more  in  succession." 

In-and-in  breeding,  carefully  followed,  permits  the  rapid 
establishment  of  a  uniform  breed ;  if  carried  too  far  it  is 
likely  to  be  accompanied  by  a  loss  in  size  and  constitu- 
tional vigor,  though  the  method  is  followed  to  a  greater 
or  less  extent  by  all  breeders. 

Pedigree  is  the  record  or  statement  of  the  ancestors 
of  an  animal,  and  is  usually  registered  only  in  the  case  of 
pure  breeds ;  it  is  useful  as  a  guide  in  tracing  inherited 
qualities.  It  is  the  custom  when  a  distinct  breed  has  been 
established  to  issue  a  herd  or  flock  book.  The  methods  of 
recording,  and  the  rules  governing  the  registry  of  pedigrees, 
are  adopted  by  the  various  Breeders'  Associations ;   and 


174         FIRST  PRINCIPLES  OF  AGRICULTURE. 

while  they  differ  somewhat  in  regard  to  form,  the  object 
is  the  same :  viz.,  to  put  in  permanent  form  a  true  record 
of  the  lineage,  character,  and  performance  of  the  indi- 
vidual. 

Value  of  Pure  Breeds.  —  Pure  breeds,  as  already 
stated,  are  the  result  of  attempts  to  secure  the  best  animal 
for  some  specific  purpose ;  and  they  can  be  relied  on  not 
only  to  accomplish  that  purpose  better  than  any  other,  but 
also  to  produce  young  that  possess  the  same  qualities.  For 
example,  a  specific  milk  or  beef  breed  of  cattle,  or  wool  or 
mutton  breed  of  sheep,  will  produce  either  milk  or  beef, 
wool  or  mutton,  better  than  milk  and  beef,  and  wool  and 
mutton.  Whereas,  in  the  common  or  native  stock  —  a 
mixture  of  many  breeds  —  a  uniformity  in  production  can- 
not be  depended  upon,  as  the  type  and  character  are  not 
fixed,  though  individuals  may  possess  superior  qualities. 

The  pure  breeds,  too,  because  of  their  fixity  of  charac- 
ter and  prepotent  power,  are  extremely  valuable  in  improv- 
ing native  stock.  The  offspring  of  a  pure-bred  sire  and 
a  native  dam  will  possess  in  greater  degree  the  character 
of  the  pure-bred  sire  than  that  of  the  mixed-bred  dam. 
A  pure-bred  sire  is,  in  such  cases,  more  than  one-half  of 
the  herd  or  flock. 

Breeding  as  a  Business.  —  To  be  a  successful  breeder 
of  live  stock  requires  large  capital,  broad  knowledge  and 
experience,  great  patience,  and  a  close  attention  to  the 
details  of  the  work.  As  a  rule,  breeding  is  more  success- 
ful when  conducted  as  a  distinct  branch  of  farming  than 
when  added  to  the  work  of  the  general  farmer.  A 
farmer  may,  however,  greatly  improve  his  stock  by  care- 
ful attention  to  the  principles  which  govern  in  breeding, 


PRINCIPLES  OF  BREEDING.  175 

and,  so  far  as  the  products  of  his  herds  and  flocks  are 
concerned,  get  much  better  results  than  are  possible  from 
common  stock.  The  best  animals  for  general  farmers, 
for  instance,  are  without  doubt  "high  grades,"  produced 
from  crossing  pure-bred  sires  with  good  common  stock. 
For  this  work  a  knowledge  of  the  conditions  of  the  farm, 
coupled  with  the  knowledge  of  the  characteristics  of  the 
leading  breeds,  should  serve  as  a  guide  for  the  selection 
of  that  breed  which  shall  best  fulfil  the  conditions.  In 
this  work  it  is  quite  as  necessary  to  have  a  sire  of  a 
high  degree  of  excellence  as  in  herds  of  pure-breds;  for 
the  stronger  the  fixed  qualities  of  the  sire,  the  more 
likely  is  he  to  impress  them  upon  his  offspring,  and  to 
overcome  the  tendencies  inherent  in  the  common  dam. 

Cross-Breeding.  —  The  crossing  of  the  pure  breeds 
has  not  always  proved  successful,  since  the  inherited 
tendencies  are  too  strong  to  admit  of  an  equal  mingling 
of  the  characteristics  of  the  parents ;  however,  many  such 
crosses  have  proved  satisfactory.  In  this  work,  breeds 
should  be  selected  which  possess  certain  qualities  in 
common,  rather  than  those  possessing  distinctly  opposite 
characters;  for  instance,  the  breeding  together  of  a  very 
small  and  a  very  large  animal  is  not  so  likely  to  result 
in  offspring  possessing  the  best  characteristics  of  both, 
as  if  the  parents  were  more  nearly  alike  in  this  and  other 
respects. 

Breeds  of  Horses.  —  The  distinct  breeds  of  horses 
are  classified  as  draft  breeds,  heavy  carriage  breeds, 
thorough-breds,  American  saddle-horses,  American  trotting- 
horses,  and  pony  breeds. 

Draft  Breeds.  —  Draft  breeds,  or  large,  heavy  horses,  — 


176         FIBST  PRINCIPLES  OF  AGRICULTURE. 

of  weight  ranging  from  one  thousand  six  hundred  to  two 
thousand  pounds,  and  specially  adapted  for  heavy  team- 
ing,—  include  the  Percheron,  and  French  and  Norman 
Draft,  originating  in  France;  the  Clydesdale,  native  of 
Scotland;  the  English  Shire  and  Suffolk  Punch,  of  Eng- 
land ;  and  the  Belgian  Draft,  native  of  Belgium.  Of 
these,  the  Clydesdale  is  perhaps  more  suitable  than  the 
others  for  heavy  farm  work.  They  are  fast  walkers,  in- 
telligent, gentle,  and  easily  broken. 

Heavy  Carriage  Breeds.  —  The  Cleveland  Bay,  French 
and  German  Coach  and  Hackney,  constitute  this  class. 
These  breeds  are  large,  active,  and  stylish,  and,  while 
bred  for  heavy  coaching,  are  well  adapted  for  road  or 
farm  work.  The  "  grades "  or  "  high  grades "  of  the 
Hackney,  particularly,  are  highly  valued,  both  for  the 
farm  and  for  general  driving.  The  use  of  sires  of  all 
these  breeds  has  proved  of  great  value  in  improving  our 
common  stock  of  horses. 

Thorough-Breds  and  American  Saddle-Horses.  — 
"Thorough-bred"  applies  only  to  the  English  running- 
horse  —  the  American  "  thorough-breds  "  being  either  im- 
ported from  England,  or  the  descendants  of  horses  so 
imported.  This  breed  had  its  origin  in  the  East,  and 
is  the  improved  breed  of  the  Arab,  Turk,  or  Barbarian. 
It  is  the  oldest  as  well  as  the  most  noted  of  all  breeds. 
The  best  qualities  of  many  breeds  are  due  to  a  greater 
or  less  admixture  of  thorough-bred  blood. 

The  American  saddle-horse  is  a  newly  formed  breed, 
which  was  originated  by  a  judicious  mingling  of  the 
blood  of  the  thorough-bred  with  the  pacer. 

The  American  Trotting-Horse.  —  This  class,   which 


PRINCIPLES  OF  B REELING.  177 

traces  directly  to  the  thorough-bred,  is  not  yet  recognized 
as  a  distinct  breed,  though  it  is  better  known  here  than 
are  those  of  the  pure  breeds. 

Pony  Breeds.  —  These  consist  of  the  Shetland, 
Welsh,  Exmoor,  Mexican,  and  Indian,  each  possessing 
special  characters,  form,  and  habits. 

Breeds  of  Cattle.  —  These  are  usually  classified  as 
dairy  and  beef  breeds,  though  many  are  regarded  as  pos- 
sessing both  dairy  and  beef  qualities  in  a  marked  degree. 

Dairy  Breeds.  —  These  may  be  further  classified  as 
butter  and  milk  breeds.  Chief  among  the  butter  breeds 
are  the  Jersey  and  Guernsey,  natives  of  the  Channel 
Islands  of  the  same  name  situated  near  the  north-west 
coast  of  France. 

Jersey.  —  This  breed  is  the  most  noted  of  all  the  dairy 
breeds,  both  for  its  general  elegance  of  proportion  and 
appearance  and  for  its  excellent  qualities.  For  butter- 
making  it  is  not  excelled.  It  has  been  brought  to  its 
present  perfection  by  very  careful  methods  of  breeding, 
in  which  one  idea,  viz.,  butter,  is  constantly  followed. 
It  is  small,  and  possesses  a  rather  delicate  constitution, 
and  is  thus  not  adapted  to  rigorous  conditions  of  climate 
and  careless  handling. 

Guernsey.  —  The  Guernsey  is  not  so  general  a  favor- 
ite as  the  Jersey;  it  is  larger  and  coarser,  though  the 
texture  of  its  skin  is  extremely  delicate.  It  is  dis- 
tinctly a  dairy  breed,  and  is  a  much  deeper  milker  than 
the  Jersey;  the  butter  product  is  also  richer  in  color 
and  of  better  texture.  A  crossing  of  the  Jersey  or 
Guernsey  upon  our  common  stock  is  extremely  useful  in 
improving  their  butter  qualities. 


178         FIRST  PRINCIPLES  OF  AGRICULTURE. 

Milk  Breeds.  —  The  chief  milk  breeds  are  the  Ayr- 
shire, Holstein-Friesian,  and  Shorthorn ;  though  the  Dutch 
Belted,  Brown  Swiss,  Devon,  and  a  few  others  have  at- 
tained considerable  prominence  in  certain  localities. 

Ayrshire.  —  This  breed  is  traceable  to  the  county  of 
Ayr  in  Scotland.  Their  chief  characteristic  is  their  ex- 
cellent milk,  good  in  quality  and  large  in  quantity.  The 
prevailing  color  is  brown  and  white ;  it  is  extremely 
hardy,  active,  and  well  adapted  for  mountain  districts. 

Holstein-Friesian.  —  The  exact  origin  of  this  breed 
is  not  well  established.  It  is  only  known  that  for  an 
indefinite  period,  anterior  to  the  records  of  history,  there 
existed  a  superior  breed  of  cattle  in  the  Duchy  of  Hol- 
stein  in  North  Holland  and  Friesland.  They  have  been 
used  by  the  English  for  two  hundred  years  to  improve 
their  stock.  In  color  they  are  almost  universally  black 
and  white.  Their  strong  points  are  large  size,  deep 
milkers,  and  hardy  constitutions. 

Shorthorn.  —  The  Shorthorn  breed  was  once  spoken 
of  as  the  Teeswater,  or  Durham.  The  date  since  which 
the  breed  has  had  a  distinct  existence  has  been  dis- 
puted, though  it  was  certainly  known  to  have  been  es- 
tablished in  the  early  years  of  the  last  century.  The 
Shorthorns  are  strong,  deep  milkers,  possess  hardy  and 
vigorous  constitutions,  and  a  great  power  of  adaptation 
to  changes  of  soil,  of  climate,  and  of  pasturage.  In 
many  sections,  and  especially  in  America,  its  breeding 
has  been  conducted  with  the  sole  view  of  the  production 
of  beef;  it  has  also  achieved  wonderful  results  through 
crossing  with  other  breeds.  The  ranch  cattle  of  the 
prairies  of  the  West  and  in  Texas   have   been   largely 


PRINCIPLES   OF  BREEDING.  179 

graded  up  with  this  breed.  Their  color  ranges  from  the 
blood  red  to  the  pure  white.  Owing  to  their  generally 
valuable  characteristics,  they  more  nearly  approach  the 
general  purpose  animal  than  any  other  breed,  though 
the  Red  Polled  and  Devon  are  also  included  in  this 
classification. 

Beef  Breeds.  —  The  chief  distinctive  beef  breeds  are 
the  Herefords,  Galloways,  and  Aberdeen,  or  Polled  Angus ; 
though,  as  already  stated,  certain  families  of  the  Short- 
horn are  bred  exclusively  for  beef. 

Hereford.  —  Hereford  cattle  originated  in  Hereford- 
shire and  adjoining  counties  in  England  ;  they  are  highly 
regarded  there,  and  have  also  met  with  great  favor  in 
the  United  States.  The  usual  color  is  a  rich,  light  or 
dark  red,  with  white  face,  throat,  and  chest.  The  use 
of  the  Hereford  for  crossing  with  other  breeds  is  not 
usually  attended  with  as  good  results  as  are  secured 
from  the  use  of  the  Shorthorn. 

Galloway.  —  The  Galloway  is  a  polled  breed,  and  de- 
rived its  name  from  the  province  of  Galloway  in  Scot- 
land. The  color  is  universally  black,  and  the  hair  long 
and  shaggy.  This  breed  has  proved  extremely  valuable 
for  the  Western  ranges.  The  animals  are  easily  accli- 
mated, active,  and  hardy. 

Aberdeen  Angus.  —  These  are  also  hornless,  and  re- 
semble the  Galloway  in  color  and  form,  though  they  are 
somewhat  less  hardy  and  mature  earlier. 

Breeds  of  Sheep.  —  The  Merino,  Southdown,  Shrop- 
shire, Hampshire,  Oxfordshire,  Cotswold,  Leicester,  Lin- 
coln, and  Horned  Dorset  are  the  leading  breeds. 

Merinos.  —  These  now  include  many  distinct  strains. 


180         FIRST  PRINCIPLES  OF  AGRICULTURE. 

They  are  the  most  widely  known  of  all  the  breeds  of 
sheep  in  America;  they  are  bred  almost  exclusively  for 
their  fine  wool,  for  which  purpose  they  are  unexcelled 
by  any  other  breed.  Their  mutton  qualities,  while  much 
improved  by  careful  breeding,  are  not  of  a  superior 
character.  They  are  hardy,  well  adapted  to  warm  cli- 
mates, and  the  rams  have  been  extensively  used  for 
breeding  up  the  flocks  in  the  South-western  States. 

Southdown.  —  Next  to  the  Merino,  the  Southdown  is 
the  most  extensively  distributed  breed  in  the  United 
States.  In  size  they  are  above  the  medium,  and  for  the 
production  of  mutton  take  first  rank.  The  ewes  are 
prolific,  and  the  lambs  are  vigorous  and  hardy. 

The  other  "down"  breeds,  viz.,  Shropshire,  Hampshire, 
and  Oxfordshire,  resemble  somewhat  the  Southdown  in 
mutton  and  wool  producing  qualities,  though  showing 
differences  in  size  and  in  their  ability  to  thrive  under 
varying  conditions. 

The  Cotswold,  Leicester,  and  Lincoln  are  bred 
chiefly  for  their  long  wool.  They  are  larger,  and,  as  a 
rule,  less  prolific  than  the  various  down  breeds ;  they  are 
extensively  used  in  crosses  to  improve  size. 

Horned  Dorset  is  an  old  and  well-established  breed 
in  England,  where  it  originated  in  the  shire  of  Dorset. 
It  is  not  largely  distributed  in  America.  In  size  these 
sheep  are  above  the  medium.  For  the  production  of 
early,  fat  lambs  this  breed  has  no  superior.  With  proper 
management  they  may  be  made  to  breed  at  all  times  of 
the  year,  are  very  prolific,  dropping  a  large  portion  of 
twins,  and  are  good  nurses.  This  breed  should  occupy 
an  important  place  here  in  the  production  of  early  lambs. 


PRINCIPLES   OF  BREEDING.  181 

Breeds  of  Swine  are  usually  divided  into  classes 
according  to  size.  The  large  breeds,  which  are  well  dis- 
tributed in  America,  include  the  Berkshire,  Poland-China, 
Duroc,  or  Jersey  Red,  and  Chester  White,  and  the  medium 
and  small  breeds,  the  Improved  Berkshire,  Cheshire,  Small 
Yorkshire,  Essex,  and  Suffolk. 

The  larger  breeds  are  more  generally  distributed  in  the 
corn-growing  States  of  the  Central  West,  and  are  well 
adapted  for  supplying  the  large  pork-packing  houses 
located  there ;  while  the  smaller  breeds  are  more  gen- 
erally distributed  in  the  more  thickly  populated  districts, 
and,  because  of  their  early  maturity,  are  better  adapted 
to  supplying  the  demands  for  light  pork  for  immediate 
consumption. 

The  Duroc,  or  Jersey  Red,  the  Chester  White,  and  the 
Poland-China  are  American  breeds.  The  Berkshire,  Chesh- 
ire, Yorkshire,  Essex,  and  Suffolk  are  English  breeds. 

The  chief  characteristics  of  a  good  hog  are  early 
maturity,  quietness  of  disposition,  and  small  percentage 
of  loss  in  dressing. 


182        FIBST  PRINCIPLES  OF  AGRICULTURE. 


CHAPTER  XV. 

The  Products  of  the  Dairy;  Their  Character  and  Composition; 
Dairy  Management. 

The  distinct  products  of  the  dairy  are  milk,  cream, 
butter,  and  cheese;  and  the  waste  or  by-products,  skim- 
milk,  buttermilk,  and  whey. 

The  primary  purpose  of  the  milk  of  the  cow  is  to  feed 
and  nourish  her  young.  The  secretion  or  formation  of  a 
larger  quantity  than  is  required  for  this  purpose  is,  there- 
fore, an  acquired  character,  and  is  the  result,  in  large 
measure,  of  artificial  conditions. 

Milk  is  a  Food  in  the  fullest  sense.  It  not  only  con- 
tains the  nutrients  necessary  to  sustain  life  and  to  cause 
growth,  viz.,  fats,  albuminoids,  carbohydrates,  and  min- 
eral salts,  but  these  exist  in  such  a  form  as  to  be  readily 
digested.  Milk  also  possesses  physical  properties  which 
distinguish  it  from  other  products.  It  is  a  white  fluid, 
throughout  which  the  fat  is  distributed  in  the  form  of 
small  globules.  The  fat  is  lighter  than  the  remainder  of 
the  fluid,  which  contains  the  albuminoids,  carbohydrates, 
and  salts  in  solution;  hence,  on  standing,  the  fat  globules 
rise  to  the  surface.  This  property  is  taken  advantage 
of  in  the  preparation  of  the  products,  cream  and  butter. 

Fat  of  Milk,  or  Butter-Fat,  consists  of  a  number  of 
distinct  kinds  of  fat,  the  chief  of  which  are  palmatin, 


THE  PRODUCTS  OF  THE  DAIRY.  183 

stearin,  olein,  and  butyrin.  These  may  be  classified  as 
fixed,  that  is,  those  which  remain  on  heating,  and  as 
volatile,  those  which  may  be  driven  off  by  heat :  fixed 
fats  are  also  of  two  kinds,  solid  and  liquid. 

The  volatile  fats  affect  the  flavor  of  dairy  products 
more  than  the  fixed,  and  it  is  the  proportion  of  liquid 
fat  (olein)  which  affects  the  solidity  of  butter.  The 
liquid  fats  increase  with  succulent  foods,  and  the  solid 
with  dry  foods. 

Albumen  and  Casein.  —  These  two  substances  con- 
stitute the  chief  albuminoids  of  milk;  and  while  they 
resemble  each  other  in  composition,  they  possess  different 
properties.  The  albumen,  which  is  contained  in  small 
amounts  not  usually  exceeding  one-half  per  cent,  is  co- 
agulated by  heat  and  not  by  acids,  while  casein  is  coagu- 
lated by  acids  and  not  by  heat.  This  property  of  casein 
is  very  important  in  the  manufacture  of  cheese. 

Milk  Sugar,  called  by  chemists  "lactose,"  possesses 
practically  the  same  food  value  as  other  sugars.  It  dif- 
fers from  cane  sugar  in  appearance  and  in  its  properties. 
When  it  is  crystallized,  it  is  very  hard,  and  it  does  not 
possess  as  high  a  sweetening  power. 

Ash,  or  Mineral  Salts,  consists  of  phosphates  of  lime, 
magnesia,  and  iron,  and  chlorides  and  sulphates  of  soda 
and  potash. 

Average  Composition  of  Milk.  —  Milk  is  not  a  pro- 
duct of  fixed  composition.  Both  the  total  amount  and 
the  proportion  of  the  constituents  are  influenced  by  a 
variety  of  conditions,  the  chief  of  which  are :  breed  of 
the  animal ;  her  age,  health,  and  individuality ;  the  method 
of  feeding  and  kind  of  food ;  period  of  lactation,  and  time 


184         FIRST  PRINCIPLES  OF  AGRICULTURE. 

and  season  of  milking.  Of  the  constituents,  fat  varies 
more  than  the  others,  though  each  may  vary  sufficiently 
to  cause  serious  differences  in  the  composition  of  the 
products  made  from  milk.  The  accompanying  analysis 
fairly  represents  the  average  amounts  and  proportions  of 
the  constituents  in  normal  milk :  — 

Water 87.50  per  cent. 

Fat 3.50 

Casein  and  Albuminoids 3.75        " 

Milk  Sugar 4.50 

Ash 0.75 

100.00 
This  average  composition  of  milk  has  served  as  the 
basis  in  many  States  for  the  enactment  of  laws  to  pre- 
vent watering  and  other  forms  of  adulteration.  It  must 
be  remembered,  however,  that  normal  or  whole  milk  will 
show  wide  variations  from  this  standard  in  both  direc- 
tions ;  that  is,  it  may  be  very  much  richer  or  very  much 
poorer.  The  solid  matter  in  milk  is  called  "  Total  Solids." 
The  Influence  of  Breed.  —  It  has  already  been  stated 
that  cattle  are  divided  into  two  classes :  on  the  one  hand, 
those  in  which  the  tendency  to  secrete  milk  is  largely 
developed ;  and  on  the  other,  those  in  which  the  tendency 
to  form  flesh  and  fat  has  been  especially  encouraged. 
The  result  of  this  careful  selection  is  the  formation  of  a 
distinct  milk  type,  in  which  the  width  and  depth  of  the 
hind  part  of  the  animal  and  the  udder  are  especially 
prominent  features. 

The  dairy  breeds  are,  however,  further  classified  into 
milk  and  butter  breeds ;  that  is,  those  which  give  a  large 
quantity  of  average  quality,  and  those  which  give  a 
smaller   quantity   of    a   higher   quality.      The    following 


THE  PRODUCTS  OF  THE  DAIRY. 


185 


table   of  averages,  the   result   of  experiments   conducted 
at  the  New  Jersey  Experiment  Station,  with  representa- 
tives  of  the   leading  dairy  breeds,  shows   their  relative 
yields,  and  the  composition  of  the  milk :  — 
Average  Yield  and  Composition  of  Milk  of  Different  Breeds. 


HJKBD. 

is* 
lis 

Percentage  of 

c 

9 

OS 

m 

2 

tea 
H 

1 

a 
"3 

s 

a 

p 

A 

00 

< 

Holstein-Friesian      .    .     . 

9.0 
11.0 
9.0 

87.30 
87.88 
87.55 

12.70 
12.12 
12.45 

3.68 
3.51 
3.65 

3.48 
3.28 
3.27 

4.84 
4.69 
4.80 

0.69 
0.64 
0.73 

9.7 

87.58 

12.42 

3.61 

3.34 

4.78 

0.69 

8.7 
8.4 

85.52 
85.66 

14.48 
14.34 

5.02 

4.78 

3.92 
3.96 

4.80 
4.85 

0.75 
0.75 

8.6 

85.09 

14.41 

4.90 

3.94 

4.83 

0.75 

While  these  results  are  not  absolute,  it  is  evident  that 
there  is  a  distinct  classification  of  breeds  based  upon  the 
relative  yield  and  quality  of  milk.  The  milk  from  animals 
which  naturally  produce  large  quantities  shows  average 
quality,  and  that  from  animals  which  produce  a  smaller 
quantity  shows  a  quality  considerably  above  the  average. 
That  the  content  of  fat  in  milk  varies  more  than  the 
other  constituents  is  also  distinctly  shown  in  this  work. 
The  variations  in  the  composition  of  milk,  due  to  breed, 
is,  therefore,  important  in  indicating  the  animals  best 
adapted  for  the  production  of  a  specific  dairy  product. 

The  Age  and  Health  of  the  Animal  also  affect 
the  composition  of  milk.  As  a  general  rule,  the  milk  of 
young  animals  is  richer  than  that  of  old ;  this  is  not 
positive,  however,  since  much  depends  upon  the  vitality, 
vigor,  health,  and  management  of  the  animals. 


186         FIRST  PRINCIPLES  OF  AGRICULTURE. 

The  Period  of  Lactation  is  the  time  which  elapses 
between  the  birth  of  the  calf  and  dryness,  and  varies 
with  different  animals  even  of  the  same  breed.  During 
this  period  the  yield  and  composition  of  the  milk  vary. 
The  milk  flow  is  greatest  and  the  quality  poorest  in  the 
beginning ;  as  the  period  increases  the  flow  gradually  falls 
off,  and,  as  a  rule,  the  quality  improves,  though  the  rate 
of  improvement  is  dependent  somewhat  upon  food  and 
management.  The  fat  globules  are  larger  at  the  begin- 
ning and  smaller  at  the  end  of  the  period. 

Colostrum A  few  days  elapse  after  the  birth  of  the 

calf  before  the  milk  is  fit  for  use.  The  product  obtained 
is  called  "colostrum,"  and  is  especially  suited  to  the 
needs  of  the  young  offspring.  It  differs  from  milk  in 
containing  a  much  larger  amount  of  solid  matter  and 
ash,  and  in  showing  but  little  sugar. 

Milk  Drawn  at  Different  Times  also  differs  in  com- 
position, though  the  influence  of  time  of  milking  is  not 
the  same  for  all  animals.  In  some  cases  the  morning's 
milk  will  be  greater  in  quantity  and  poorer  in  quality  than 
the  evening's  milk,  while  in  others  the  reverse  is  the 
case;  hence  the  variation  in  the  milk  of  a  herd  is  not 
so  noticeable  as  that  from  individual  cows. 

It  is  also  a  matter  of  common  observation  that  the  milk 
first  drawn  is  poorer,  particularly  in  fat,  than  the  "  strip- 
pings,"  or  that  last  drawn;  frequently  the  " strippings," 
or  last  pint  drawn,  contain  six  to  eight  times  more  fat 
than  the  first  pint,  while  the  other  constituents,  albumi- 
noids and  sugar,  are  more  evenly  distributed ;  this  vari- 
ation in  composition,  in  connection  with  the  fact  that 
the  fat  globules  are  larger  in  the  "  strippings  "  than  in 


THE  PRODUCTS  OF  THE  DAIRY.  187 

the  milk  first  drawn,  indicates  that  the  fat  rises  in  the 
udder. 

The  Influence  of  Pood  is  perhaps  greater  than  any- 
other  factor  in  determining  the  profit  that  may  be  de- 
rived from  the  dairy ;  its  influence  is  felt,  not  only  on  the 
quantity  of  milk  produced,  but  on  the  quality  of  the 
products  derived  from  it.  A  specific  breed  possesses  cer- 
tain capabilities,  the  value  of  which  are  dependent  in 
large  measure  upon  the  food  that  is  supplied. 

By  proper  feeding  is  meant,  not  only  that  the  animal 
should  receive  a  sufficient  amount  of  nutriment  in  the 
right  proportions,  but  also  that  the  materials  furnishing 
the  nutrients  should  be  clean  and  wholesome,  and  free 
from  any  substance  that  may  injure  the  quality  of  the 
product. 

Pasture  and  Hay.  —  Pastures  and  green  foods,  for 
instance,  composed  only  of  the  true  grasses  and  clovers, 
are  nutritious  and  wholesome,  and  can  have  no  injurious 
effect  upon  the  health  of  the  animal  or  the  quality  of 
the  product;  while  those  which  include  a  large  number 
of  weeds  may  not  only  be  dangerous  to  the  health  of 
the  animal,  but  may  cause  an  undesirable  flavor  in  the 
milk,  and  an  inferior  quality  of  the  butter  or  cheese  pro- 
duced from  it.  Hay  free  from  weeds,  if  well  made  and 
the  desirable  properties  retained,  is  an  excellent  food ;  but 
if  improperly  cured  and  the  characteristic  odor  destroyed, 
and  so  badly  stored  as  to  cause  it  to  heat  and  mould,  its 
feeding  will  result  in  a  much  poorer  quality  of  product. 

Coarse   Products   and  Concentrated  Feeds The 

coarse  products,  straw  and  stalks,  and  the  concentrated 
feeds  composed  of  the  cereal  grains  and  refuse  mill  pro- 


188         FIRST  PRINCIPLES  OF  AGRICULTURE. 

ducts,  if  clean  and  sweet,  affect  the  quality  of  milk 
only  by  virtue  of  the  variations  in  their  feeding  value, 
though  the  character  of  the  products  made  from  it  may 
be  influenced  to  some  extent.  The  feeding  of  cotton- 
seed, for  instance,  has  a  tendency  to  increase  the  pro- 
portion of  solid  fat,  while  gluten  meal,  on  the  other 
hand,  is  said  to  increase  the  proportion  of  liquid  fat. 

Useful  Succulent  Foods,  as  turnips,  swedes,  mangel- 
wurzels,  cabbage,  etc.,  also  affect  the  flavor  of  the  milk; 
and,  in  order  to  prevent  as  far  as  possible  their  unfa- 
vorable effect,  they  should  be  fed  immediately  after 
milking.  Wet  brewers'  grains,  distillery  refuse,  and  en- 
silage in  an  advanced  state  of  fermentation,  also  exert 
an  unfavorable  influence  on  the  quality  of  the  milk. 

Changes  in  Milk.  — It  is  well  known  that  milk  from 
healthy  cows,  even  under  good  practical  conditions  of 
preservation,  will  remain  sweet  but  a  short  time ;  though, 
if  it  could  be  drawn  and  placed  so  that  no  air  could 
come  in  contact  with  it,  it  would  always  remain  sweet. 
The  changes  in  milk,  or  tendency  to  sour,  are  caused  by 
the  entrance  into  it  of  ferments,  or  minute  organisms 
called  "  bacteria ; "  and  milk  possesses  in  a  marked  de- 
gree those  properties  which,  given  a  suitable  temperature, 
favor  their  rapid  development. 

Good  and  Bad  Ferments.  —  These  bacteria  are  of 
two  classes,  one  of  which  includes  those  called  "  friendly," 
which  are  necessary  or  helpful  in  the  making  of  butter 
or  cheese,  and  the  other,  "  unfriendly,"  or  those  which 
introduce  bad  qualities  into  the  milk  and  its  products. 
The  ferments  that  injuriously  affect  milk  are  more  abun- 
dant in  warm  weather,  in  closed  buildings,  and  around 


THE  PRODUCTS  OF  THE  DAIRY.  189 

decaying  matter,  than  in  cold  weather  and  in  the  open 
air,  because  warmth,  impure  air,  and  unclean  conditions 
are  favorable  for  their  growth,  while  a  low  temperature, 
sunshine,  and  pure  air  prevent  their  rapid  development. 

Cleanliness  is  Essential  to  Good  Milk  Supply.  — 
Milk  from  healthy  cows,  that  are  fed  clean,  wholesome 
food  and  pure  water,  and  are  kept  in  clean  stables,  when 
drawn  by  clean  milkers,  and  then  rapidly  cooled  and 
kept  in  a  clean  place,  will  keep  longer  than  that  drawn 
from  animals  that  are  poorly  fed,  improperly  housed,  and 
badly  cleaned ;  since  in  the  one  case  the  conditions  are 
such  as  to  reduce  the  influence  of  the  "unfriendly"  bac- 
teria, while  in  the  other  the  conditions  are  favorable  for 
their  development  and  introduction  into  the  milk. 

It  is  not  only  essential  that  the  animal,  the  stables, 
the  milker,  the  utensils,  the  dairy-room  or  cellar,  should 
be  kept  as  clean  as  possible,  but  that  all  manner  of  de- 
caying matter  about  the  farm  should  be  prevented  or 
removed.  Fermenting  foods,  bedding  consisting  of  decay- 
ing straw  or  hay,  muddy  and  filthy  water  in  the  pastures, 
are  frequently  the  cause  of  bad  taints  in  milk.  These 
not  only  destroy  in  large  measure  its  good  qualities,  but 
render  its  use  dangerous.  Furthermore,  no  milk  from 
diseased  animals,  or  that  which  has  been  exposed  to  the 
germs  of  infectious  human  diseases  that  may  be  carried 
and  introduced  by  milkers,  or  diseases  which  can  be  in- 
troduced through  the  animals  themselves  by  means  of 
contaminated  water  supply,  should  ever  be  offered  for 
sale  direct  as  milk,  or  indirectly  as  butter  or  cheese. 

Cream  consists  of  the  fat  globules  mixed  with  more 
or  less  of  the  other  constituents  of  milk.     Its  richness 


190         FIRST  PRINCIPLES  OF  AGRICULTURE. 

in  fat  depends  upon  the  quality  of  the  milk  from  which 
it  is  derived,  and  upon  the  method  used  in  creaming.  It 
is,  therefore,  not  a  product  of  uniform  composition ;  in 
fact,  it  is  much  less  uniform  than  milk,  its  content  of 
fat  —  the  chief  constituent  of  value  in  it  —  ranging  from 
as  low  as  ten  per  cent  to  as  high  as  forty  per  cent. 

Its  purchase  or  sale,  either  as  food  for  families  or  for 
the  production  of  butter  at  creameries,  should  be  based  on 
the  actual  content  of  fat  rather  than  its  volume  or  measure. 

Systems  of  Creaming.  —  These  are  divided  into  two 
classes,  —  first,  the  setting  systems,  in  which  the  cream 
rises  under  natural  conditions ;  and  second,  centrifugal 
systems,  in  which  mechanical  force  is  used. 

The  simplest  setting  system  is  the  open-air  shallow 
pan;  it  is  also  the  most  common,  but  it  does  not  give 
the  best  results.  In  order  to  get  the  largest  quantity  of 
cream  by  this  method,  the  milk  has  to  stand  too  long, 
which  endangers  the  quality  of  the  butter;  besides,  the 
long  exposure  to  the  air  induces  rapid  changes  and  sour- 
ing, which  render  the  skim-milk  less  valuable  as  food  for 
animals,  and  make  it  unfit  for  human  food.  The  deep- 
setting  systems  permit  of  a  better  regulation  of  the  tem- 
perature, and  of  a  more  perfect  protection  from  the  air; 
while  the  rapidity  and  completeness  of  the  creaming  is 
not  decreased. 

Mechanical  separation  is  more  economical  of  space, 
time,  and  labor,  and  a  larger  percentage  of  the  fat  of 
the  milk  is  obtained  by  it  than  by  any  other  method ; 
besides,  perfectly  fresh  cream  and  skim-milk  can  be  im- 
mediately obtained  by  this  system.  This  system  of  cream- 
ing has  taken  the  place  of  the  others  to  a  great  extent 


THE  PRODUCTS  OF  THE  DAIRY.  191 

in  large  dairies  and  creameries,  though  the  cost  of  the 
separator  and  the  power  required  to  run  it  have  pre- 
vented its  rapid  adoption  in  the  small  home  dairy. 

The  various  large  machines  have  now  reached  a  remark- 
able degree  of  perfection ;  and  it  is  only  a  question  of  time 
before  those  adapted  for  the  small  dairy,  both  in  point 
of  cost  and  power,  will  be  available. 

Butter.  —  Butter  consists  of  the  fat  globules  of  milk 
gathered  into  a  solid  form.  Like  other  products  of  the 
dairy,  it  is  subject  to  wide  variations  in  composition  and 
quality.  Good  butter  should  contain  at  least  eighty-five 
per  cent  of  pure  butter  fat,  not  more  than  twelve  per  cent 
of  moisture,  and  less  than  one  per  cent  of  casein.  The 
content  of  ash,  or  mineral  salts,  depends  upon  methods 
of  salting,  though  it  should  not  exceed  one  and  one-half 
per  cent. 

The  yield  of  butter  from  a  given  quantity  of  milk  de- 
pends chiefly  upon  the  amount  of  fat  in  the  milk,  and  the 
composition  of  the  product  secured.  If  milk  is  bought 
for  butter-making,  it  should  be  paid  for  on  the  basis  of 
content  of  butter  fat,  rather  than  by  weight  or  volume. 
The  yield  of  butter  from  a  given  quantity  of  fat  in  differ- 
ent lots  of  milk  also  varies  slightly,  since  the  fat  in  all 
milks  cannot  be  uniformly  recovered  as  butter  even  under 
uniform  methods  of  treatment.  This  is  believed  to  be 
largely  due  to  differences  in  the  size  of  the  fat  globules ; 
the  larger  the  globule  the  greater  the  proportion  of 
fat  recovered ;  in  practice,  however,  this  point  is  largely 
disregarded. 

The  properties  of  butter  which  determine  its  edible 
quality  and  appearance  are  flavor,  keeping  quality,  solid- 


192        FIRST  PRINCIPLES  OF  AGRICULTURE. 

ity,  texture,  and  color.  These  are  the  result  in  large 
measure  of  the  management  of  the  milk  and  cream,  and 
the  method  of  making  the  butter.  Good  flavor,  for  in- 
stance, belongs  to  some  extent  to  certain  of  the  fats  them- 
selves, though  largely  to  the  changes  which  occur  in  the 
ripening  of  the  cream,  a  process  of  fermentation  which 
can  be  controlled  by  the  butter-maker.  In  fact,  certain 
ferments  have  been  discovered  and  isolated,  which,  if 
added  to  the  cream,  will  give  to  the  butter  the  delicate 
flavor  so  pleasing  to  the  palate.  This  method  of  securing 
uniform  quality  in  respect  to  flavor  is  likely  to  become 
an  important  feature  of  butter-making. 

Bad  Flavors  or  Odors  may  be  due  to  certain  foods,  as 
cabbage,  poor  hay,  fermenting  brewers'  grains,  and  ensi- 
lage, and  to  such  weeds  as  garlic.  Butter  will  also  absorb 
the  odors  of  foods,  decaying  substances,  etc.,  with  which 
it  comes  in  immediate  contact;  hence  products  possessing 
distinct  flavors  should  not  be  stored  in  the  dairy  room. 

The  Keeping  Quality  of  butter  is  governed  to  a  great 
degree  by  the  method  of  making.  If  the  cream  is  properly 
ripened  and  churned,  the  butter  well  worked  and  evenly 
salted,  it  will,  even  under  ordinary  conditions,  retain  its 
original  quality  for  a  long  time ;  while  if  the  processes 
have  been  carelessly  conducted,  the  buttermilk  not  com- 
pletely removed,  and  unevenly  salted,  it  will  soon  lose  its 
good  qualities;  the  casein  which  has  been  left  in  it  will 
decay,  and  cause  it  to  become  rancid. 

Texture.  —  When  butter  is  solid,  and  shows  a  decided 
granular  structure  rather  than  a  greasy  appearance  when 
broken,  it  is  said  to  possess  good  texture.  This  is  gov- 
erned by  the  character  of  the  milk  and  method  of  manage- 


THE  PRODUCTS   OF  THE  DAIRY.  193 

ment.  Milk  which  contains  large  fat  globules,  as  that  from 
the  Jersey  and  Guernsey,  will,  under  the  same  methods  of 
making,  produce  butter  of  a  better  texture  than  that  from 
the  milk  containing  small  fat  globules.  Too  much  han- 
dling, and  too  high  a  temperature  in  making  the  butter, 
also  injure  the  texture. 

The  Natural  Color  of  butter  is  due  to  a  substance  in 
milk  called  "lacto-chrome."  The  butter  from  the  distinct 
butter  breeds  or  their  "  grades  "  possesses  a  better  natural 
color  as  a  rule  than  that  from  the  milk  breeds. 

Sweet  Cream  Butter  is  used  to  a  limited  extent  in 
certain  localities ;  it  is  made  from  unripened  cream,  and  is 
preferred  by  certain  customers  because  only  the  original 
flavors  are  retained. 

Cheese.  —  Cheese  consists  of  the  casein  of  the  milk 
with  more  or  less  of  its  butter  fat ;  it  is  of  two  distinct 
kinds  j  viz.,  whole-milk  cheese,  which  contains  all  the  fat 
of  the  milk  that  can  be  recovered  in  the  process  of  manu- 
facture, and  skim-milk  cheese,  where  the  fat  in  the 
milk  has  been'  partially  removed  before  it  is  made  into 
cheese.  • 

Manufacture  of  Cheese.  —  The  principles  involved  in 
the  manufacture  of  cheese  are  practically  the  same  for 
the  many  different  varieties.  The  various  operations  in- 
clude the  coagulation  of  the  casein,  removal  of  the  whey, 
salting,  pressing,  and  ripening.  The  composition  of  whole- 
milk  cheese,  as  well  as  its  edible  qualities,  depends  upon 
the  composition  of  the  milk  used  and  the  methods  of 
manufacture.  Recent  experiments  have  shown  that,  other 
things  being  equal,  the  fat  in  milk  measures  the  amount 
and   quality  of  cheese  that  may  be  made  from  it.     The 


104  FIRST  PRINCIPLES   OF  AGRICULTURE. 

best  cheese  is  produced,  and  the  least  loss  occurs  in  manu- 
facture, from  milk  rich  in  fat. 

Good  Cheese  should  possess  richness,  that  is,  good 
proportions  of  fat  and  casein,  good  flavor,  keeping  quali- 
ties, and  firmness  of  texture ;  and  can  only  be  secured 
by  very  careful  attention  to  the  details  in  the  numerous 
operations  required  in  its  manufacture. 

Cheese  as  Food.  —  Whole-milk  cheese,  though  vary- 
ing in  composition,  is  a  very  nutritious  food,  since  it  is 
rich  in  the  most  valuable  nutrients,  casein  and  fat.  Good 
products  contain  as  high  as  thirty-five  to  forty  per  cent 
of  fat,  twenty-five  to  thirty  per  cent  of  casein,  and  as  low- 
as  twenty  per  cent  of  water.  Skim-milk  cheese,  though 
an  excellent  food,  is  less  valuable ;  it  contains  more  water 
and  much  less  fat. 

Skim-milk.  —  This  consists  of  the  remainder  of  the 
milk  after  the  removal  of  the  fat,  and  varies  in  composi- 
tion according  to  the  completeness  of  skimming,  or  separa- 
tion of  fat ;  as  a  rule,  separator  skim-milk  is  poorer  in  fat 
than  that  derived  by  other  methods.  Skim-milk  shows 
less  total  solid  matter  and  different  proportion  of  the 
food  constituents  than  whole  milk ;  fat  is  the  most  vari- 
able constituent.  It  ranges  from  two-tenths  of  one  per 
cent  to  one  per  cent;  casein  and  ash  are  slightly  less, 
while  milk  sugar  is  somewhat  greater  in  amount  than  in 
whole  milk.  An  average  composition  would  probably 
show :  — 

Water 90.00  per  cent. 

Fat 0.80 

Casein  and  Albumen 3.60         " 

Sugar 4.90 

Ash 0.70 


THE  PRODUCTS   OF  THE  DAIRY.  195 

As  a  Food,  skim-milk,  though  dilute,  is,  when  sweet, 
a  wholesome  and  nutritious  human  food.  It  is  also,  both 
in  its  sweet  and  sour  state,  an  excellent  animal  food, 
and  is  especially  adapted  for  pigs  and  calves ;  though, 
because  of  its  highly  nitrogenous  character  and  narrow 
nutritive  ratio,  it  should  be  used  in  connection  with  those 
of  a  fatty  or  carbonaceous  nature,  which  will  widen  the 
ratio.  Skim-milk  and  flaxseed  meal  —  which  is  rich  in 
fat  —  make  an  excellent  and  well  proportioned  ration 
for  young  calves;  while  skim-milk  and  wheat  middlings, 
or  other  products  showing  a  high  content  of  digestible 
carbohydrates  and  fat,  make  a  good  and  economical  ra- 
tion for  pigs. 

Buttermilk  contains  the  casein  and  sugar  retained  in 
the  cream  from  which  butter  is  made,  and  such  propor- 
tions of  the  fat  as  are  not  recovered.  It  differs  but  little 
in  composition  from  skim-milk,  and  has  about  the  same 
feeding  value,  though  usually  containing  more  fat  and 
casein,  and  less  sugar ;  it  is  also  liable  to  considerable  vari- 
ation, owing  to  differences  in  methods  of  obtaining  the 
cream  and  of  churning. 

"Whey  is  the  residue  from  the  manufacture  of  cheese. 
It  is  more  dilute  than  the  other  refuse  products,  and 
as  a  food  is  chiefly  valuable  for  its  content  of   sugar. 

Dairying.  —  The  success  and  profit  of  the  dairy  de- 
pend upon  a  number  of  conditions,  which  should  be 
carefully  considered.  The  situation  in  reference  to  homo 
supplies,  which  include  water,  and  natural  fertility  of 
soil,  access  to  good  wholesome  foods,  location  and  char- 
acter of  markets,  and  the  relative  profitableness  of  dairy- 
ing and  other  lines  of  farming,  should  all  be  carefully 
studied  before   entering  upon  the  business. 


196         FIRST  PRINCIPLES   OF  AGRICULTURE. 

The  Selection  of  a  Specialty  is  also  important ;  for, 
while  a  series  of  products  may  be  made,  the  adoption  of 
a  single  line  usually  results  in  a  greater  concentration 
of  energy,  and  hence  a  better  product.  This  involves 
a  knowledge  of  the  special  characteristics  of  the  differ- 
ent breeds,  and  the  principles  that  govern  in  their  selec- 
tion, management,  care,  and  improvement. 

Testing  the  Animals.  —  The  profits  of  the  dairy  are 
also  governed  in  large  measure  by  the  yield  and  quality 
of  the  milk ;  hence  careful  records  should  be  kept  of 
individual  animals  in  these  respects.  It  has  already  been 
shown  that  the  yield  and  quality  of  the  dairy  products, 
cream,  butter,  and  cheese,  are  measured  by  the  content 
of  butter-fat  in  the  milk ;  it  is,  therefore,  of  the  great- 
est importance  that  the  content  of  fat  in  the  milk  of 
each  animal  should  be  tested.  This  may  be  accurately 
and  rapidly  accomplished  by  what  are  known  as  semi- 
chemical  methods ;  of  these  the  "  Babcock  Test,"  de- 
vised by  Dr.  S.  M.  Babcock  of  the  Wisconsin  Experiment 
Station,  furnishes  accurate  results,  and  is  so  simple  in 
operation  as  to  be  readily  performed  by  any  careful 
dairyman. 

A  careful  study  of  the  animals  in  these  respects  teaches 
the  dairyman  the  actual  value  of  each,  hence  only  those 
which  are  profitable  need  be  kept. 

Dairy  Products  and  Soil  Fertility.  —  The  relation 
of  the  sale  of  the  various  dairy  products  to  soil  ex- 
haustion is  frequently  disregarded  in  the  selection  of 
specific  lines,  though  it  is  a  matter  of  some  importance. 
If  whole  milk  is  sold,  there  is  removed  from  the  farm 
for  each  ton  sold  an  average  of  twelve  pounds  of  nitro- 


THE  PRODUCTS   OF  THE  DAIRY.  197 

gen,  four  and  a  half  pounds  of  phosphoric  acid, .  and 
three  and  a  half  pounds  of  potash.  If  it  is  manufac- 
tured into  cheese,  the  mineral  salts  are  largely  retained 
in  the  whey,  and  nitrogen  only  is  removed.  If  it  is 
manufactured  into  cream  or  butter,  and  the  skim-milk 
and  buttermilk  —  foods  of  considerable  value  —  are  re- 
tained, practically  no  loss  in  fertility  results.  The 
exact  value  of  these  relations  will  differ  with  different 
conditions,  such  as  relative  prices  received  for  the  vari- 
ous products,  the  cost  of  actual  fertilizing  constituents, 
and  the  usefulness  of  the  foods,  skim-milk  and  butter- 
milk; hence  it  can,  of  course,  be  determined  only  by  the 
individual  dairyman. 

The  Purchase  of  Poods  and  Methods  of  Feeding 
are  also  valuable  factors.  The  feeds  should  not  only  be 
well  adapted  in  themselves,  but  should  be  so  adjusted 
to  others  in  the  ration  as  to  result  in  the  greatest  pos- 
sible product  for  the  least  outlay.  The  care  of  the  an- 
imals should  also  be  kindly,  regular,  and  punctual,  and 
all  the  processes  of  the  dairy  carried  out  in  such  a 
manner  as  to  guarantee  the  highest  quality  of  product. 


APPENDIX. 


CONTAINING    TABLES 

SHOWING    THE 

Composition  of  Fertilizing  Materials,  Farm  Manures, 
Fodders,  Feeds;  the  Coefficients  of  Digestibility  of 
Various  Feeding  Stuffs;  Fuel  Value  of  Food;  Feed- 
ing Standards  for  Different  Animals  and  Different 
Purposes  of  Feeding;  and  the  Fertilizer  Constituents 
Contained  in  the  Chief  Farm  Crops  and  Concentrated 
Feeds. 


200 


APPENDIX. 


COMPOSITION   OF  FERTILIZING  MATERIALS. 
Table  I.    Nitrogenous  Materials. 


Pounds  Per  Hundred. 

Nitrogen. 

Total 
Phos.  Acid. 

Potash. 

Dried  Blood  (high  grade)      .... 

15J  to  10 
19    to  20J 
12    to  14 

10  to  11 

11  to  12i 
5    to    6 
7   to   9 
6i  to   7J 
5    to    6 

3    to   5 
1    to    2 
11    to  14 
6   to   8 
1J  to   2 
1    to    1J 

2  to  3 
1  to  1J 

Table  II.    Phosphatic  Materials. 


Pounds  Per  Hundred. 


Nitrogen. 


Phosphoric  Acid. 


Total. 


Available.    Insoluble 


S.  C.  Rock  Phosphate  .  .  . 
S.  C.  Rock  Superphosphate, 
Fla.  Land  Rock  Phosphate  . 
Fla.  Pebble  Phosphate  .  . 
Fla.  Superphosphate    .    .    . 

Bone-black 

Bone-black  Superphosphate, 

Ground  Bone    

Steamed  Bone 

Bone  (dissolved) 


2}  to  4} 
1J  to  21 
2  to  3 


26  to  28 
13  to  16 
33  to  35 
26  to  32 

16  to  20 
32  to  36 

17  to  18 
20  to  25 
22  to  29 
15  to  17 


14  to  10 

15  to  17 

5  to  8 

6  to  9 
13  to  15 


26  to  28 
1  to  3 

33  to  35 

26  to  32 
1  to  4 

32  to  36 

1  to  2 

15  to  17 

16  to  20 

2  to  3 


APPENDIX. 


201 


Table  HI.    Potassic  Materials. 


Pounds  Per  Hundred. 

Actual 
Potash. 

Total 
Phos. 
Acid. 

Lime. 

Nitro- 
gen. 

Chlorine. 

Muriate  of  Potash    .... 
Sulph.  of  Potash  (high  grade) 
Douhle  Sulph.  of  Potash  and 

Cottonseed  Hull  Ashes     .     . 
Wood  Ashes  (unleached)  .    . 
Wood  Ashes  (leached) .     .     . 

50 

48  to  52 

26  to  30 
12  to  12$ 
16  to  20 
20  to  30 
2to    8 
Ito    2 
5to    8 

7  to  9 
Ito  2 
1  tolj 

10 

30  to  35 
35  to  40 
3.5 

2  to  3 

45  to  48 
\  to  1J 

1J  to  2i 
30  to  32 
42  to  46 

Table  IV.     Average  Composition  of  Farm  Manures. 


Farm  Manures. 


Pounds  Per  Hundred. 


Total 
Phos. 
Acid. 

Potash. 

0.16 

0.40 

0.28 

0.53 

0.23 

0.67 

0.19 

0.60 

1.54 

0.85 

0.26 

0.63 

Lime. 


Cow  Manure  (fresh)  . 
Horse  Manure  (fresh) 
Sheep  Manure  (fresh) 
Hog  Manure  (fresh)  . 
Hen  Dung  (fresh) .  . 
Mixed  Stable  Manure 


0.34 
0.58 
0.83 
0.45 
1.63 
0.50 


0.31 
0.21 
0.33 
0.08 
0.24 
0.70 


202 


APPENDIX. 


Table  V.    Average  Composition  of  Fodders  and  Feeds. 


Kind  of  Feeding  Stuff. 


Pounds  per  Hundred. 


GREEN  FODDERS  AND  ENSILAGE. 

Pasture  Grass 

Orchard  Grass  (in  bloom) 

Timothy 

Corn  (Maize)  Fodder  — 

Flint  varieties 

Dent  varieties 

Sweet  varieties 

Red  Clover 

Alsike  Clover  (in  bloom) 

Alfalfa  (Lucerne) . 

Crimson  Clover  (just  heading)  .  .  . 
Crimson  Clover  (full  bloom)  .... 

Cow  Pea 

Sorghum  (whole  plant) 

Kye  Fodder     

Oat  Fodder 

Corn  (Maize)  Ensilage 

HAY  AND   DRY   COARSK   FODDERS. 

Corn  (Maize)  Fodder 

Corn  (Maize)  Stalks 

Hay,  Mixed  Meadow  Grasses      .    .    . 

Timothy  Hay 

Hay,  Hungarian  Grass 

Red  Clover  Hay 

Alsike  Clover  Hay 

Alfalfa  (Lucerne)  Hay 

"Wheat  Straw 

Rye  Straw 

Oat  Straw 

ROOTS  AND  TUBERS. 

Mangels 

Rutabagas 

Turnips : 

Red  Beets 

Sugar  Beets 

Carrots 

Potatoes 

Sweet  Potatoes 


70.3 
73.0 
61.6 

79.8 
79.0 
79.1 
70.8 
74.8 
71.8 
89.2 
81.5 
83.5 
79.4 
76.6 
62.2 
79.1 

42.2 
10.2 
16.0 
13.6 
7.7 
15.3 
9.7 
8.4 
9.6 
7.1 
9.2 

90.9 
88.6 
90.5 
88.5 
86.5 
88.6 
79.1 
72.4 


1.2 
0.9 
1.2 

0.7 
0.5 
0.5 
1.1 
0.9 
1.0 
0.4 
0.6 
0.4 
0.5 
0.6 
1.4 
0.8 

1.6 
1.2 
2.1 
2.5 
2.1 
3.3 
2.9 
2.7 
1.3 
1.2 
2.3 

0.2 
0.2 
0.2 
0.1 
0.1 
0.4 
0.1 
0.3 


6.5 
8.2 
11.8 

4.3 
5.6 
4.4 
8.1 
7.4 
7.4 
1.8 
5.1 
4.7 
6.1 
11.6 
11.2 
6.0 

14.3 
28.2 
29.9 
28.9 
27.7 
24.8 
25.6 
25.0 
38.1 
38.9 
37.0 

0.9 
1.3 
1.2 
0.9 
0.9 
1.3 
0.4 
0.9 


4.7 
2.6 
3.1 

2.0 
1.7 
1.9 
4.4 
3.9 
4.8 
2.5 
3.2 
2.5 
1.3 
2.6 
3.4 
1.7 

4.5 

4.6 

6.4 

5.9 

7.5 

12.3 

12.8 

14.3 

3.4 

3.0 

4.0 

1.4 
1.2 
1.1 
1.5 
1.8 
1.1 
2.1 
1.1 


2.8 
2.0 
2.1 

1.1 
1.2 
1.3 
2.1 
2.0 
2.7 
1.2 
1.5 
1.7 
1.1 
1.8 
2.5 
1.4 

2.7 
5.2 
4.6 
4.4 
6.0 
6.2 
8.3 
7.4 
4.2 
3.2 
5.1 

1.1 
1.2 
0.8 
1.0 
0.9 
1.0 
0.9 
1.3 


APPENDIX. 


203 


Table  V.    Average  Composition  of  Fodders  and  Feeds. 

{Concluded.) 


Kind  of  Feeding  Stuff. 


Pounds  per  Hundred. 

d 

» 

.j 

M 

0 

A 

s 

fc 

s 

A 

< 

4> 

o 

9 

<B 

•o 

■a 

-3 

73 

oS 

s 

3 

3 

3 

£ 

t. 

&* 

o 

O 

o 

O 

GRAINS  AND  OTHER  SEEDS. 

Corn  (Maize)  — 

Flint 

Dent 

Sweet 

Wheat  (winter  varieties) 

Rye 

Oats 

Buckwheat 

MILL  PRODUCTS  AND  REFU8E  FEEDS. 

Corn  (Maize)  Meal 

Corn  and  Cob  Meal 

Corn  Bran  

"Wheat  Bran  (all  analyse.-) 

Wheat  Shorts 

AVheat  Middlings 

Wheat  Screenings 

Rye  Bran 

Rye  Shorts 

Buckwheat  Bran 

Buckwheat  Middlings     ....... 

Rice  Bran 

Malt  Sprouts 

Brewers'  Grains 

Brewers'  Grains,  dried 

Gluten  Meal 

Chicago  Gluten  Meal 

Buffalo  Gluten  Feed 

Grano  Gluten  Feed 

Ceroalino  Feed 

Hominy  Chop , 

Corn  Oil  Meal , 

Cottonseed  Meal , 

Linseed  Meal  (old  process)     .    .     .    .    , 
Linseed  Meal  (new  process)    .    .    .    .    , 


11.3 

5.0 

1.7 

10.5 

1.4 

10.6 

5.0 

2.2 

10.3 

1.5 

8.8 

8.1 

2.8 

11.6 

1.9 

10.5 

2.1 

1.8 

11.8 

1.8 

11.6 

1.7 

1.7 

10.6 

1.9 

11.0 

5.0 

9.5 

11.8 

3.0 

12.6 

2.2 

8.7 

10.0 

2.0 

14.4 

3.8 

1.9 

9.3 

1.4 

15.1 

3.5 

6.6 

8.5 

1.5 

8.5 

8.1 

11.5 

11.4 

0.8 

11.7 

4.1 

8.9 

15.4 

5.9 

11.7 

4.5 

7.0 

15.1 

4.4 

11.8 

4.0 

4.4 

15.7 

3.2 

11.6 

3.0 

4.9 

12.5 

2.9 

11.6 

2.8 

3.4 

14.4 

3.5 

9.3 

2.8 

5.1 

18.0 

4.9 

12.9 

5.9 

13.4 

22.1 

4.3 

12.8 

7.5 

3.8 

28.0 

5.0 

9.7 

8.8 

9.5 

12.1 

10.0 

9.3 

1.9 

10.6 

25.9 

6.5 

75.7 

1.7 

3.7 

5.9 

0.9 

8.7 

6.6 

13.1 

22.7 

3.8 

8.0 

14.6 

1.6 

33.0 

1.3 

9.1 

5.5 

1.3 

33.7 

0.9 

8.3 

12.7 

6.7 

21.5 

0.9 

6.0 

14.2 

11.4 

31.0 

2.7 

9.C 

8.1 

6.8 

10.6 

2.6 

8.7 

9.7 

3.4 

11.3 

2.9 

9.0 

13.5 

6.7 

24.8 

2.4 

8.0 

12.6 

r>.<> 

42.4 

7.2 

9.2 

7.7 

8.4 

33.5 

5.7 

10.1 

3.0 

9.5 

33.2 

5.8 

204 


APPENDIX. 


Table  VI.    Coefficients   of  Digestibility  of  American   Feed 

Stuffs. 

EXPERIMENTS  WITH  RUMINANTS. 


Kind  of  Fodder. 


£•§ 


HAY  AND  DRY  COARSE   FODDERS. 

Timothy  Hay 

Hay  of  Mixed  Grasses  (rich  in  protein) .    . 

Hay  of  Orchard  Grass 

Hay  of  Red  Top 

Dried  Pasture  Grass 

Oat  Straw 


HAY  OF  LEGUMES. 

Cow-pea  Vine  Hay  (fair  quality)  .  . 
Clover  Hay  (late  bloom,  fair  quality) 
Clover  Hay  (good  quality)      .... 

Crimson  Clover  Hay 

Alsike  Clover 

Alfalfa  (Lucerne)  . 


CORN  FODDERS  (PARTIALLY  AIR  DRY). 

Corn  Stalks  (whole  plan;) 

Corn  Stalks  (leaves  of) 

Corn  Fodder 

Sweet  Corn  Fodder  (mature) 

GREEN  FODDERS. 

Corn  Fodder 

Sweet  Corn  Fodder  (milk) 

Sorghum 

Pasture  Grass 

Soiling  Rye  (formation  of  head) 

Soiling  Clover  (late  blossom) 

Corn  Ensilage 


ROOTS,  TUBERS,  ETC. 


Potatoes  . 
Sugar  Beets 
Mangels 


Corn  (Maize)  Meal 
Corn  and  Cob  Meal 
Pea  Meal  .... 
Raw  Cotton  Seed  . 
Soja-bean  Meal .    . 


100 
43 


Gl 
49 
56 
51 
00 
38 

60 
63 

43 
46 
60 
48 

52 
63 

74 

74 

76 
74 
74 
63 

74 

G5 


60 


92 
84 
66 
87 
86 


66 
56 

4!) 
69 
66 

09 

62 
56 
66 
64 

53 

77 
40 
70 
79 
07 
52 

44 
01 

75 

60 

52 
83 
68 

91 


APPENDIX. 


205 


Table  VI.     Coefficients  of  Digestibility   of  American  Feed 
Stuffs.  —  Concluded. 

EXPERIMENTS  WITH  RUMINANTS. 


Kind  of  Fodder. 


r.Y-PRODUCTS. 

Cottonseed  Meal 

Chicago  Gluten  Meal     .... 

Gluten  Meal 

Buffalo  Gluten  Feed 

Chicago  Maize  Feed 

Winter  Wheat  Bran 

Spring  Wheat  Bran 

Wheat  Middlings 

New-process  Linseed  Meal     .    . 
Old-process  Linseed  Meal .    .    . 

Malt  Sprouts 

Brewers'  Grains  Dried  .... 


100 
82 
28 
24 
36 
74 
57 
34 
53 


93 
97 
93 
94 
92 
65 
76 
85 
94 
89 
100 
91 


79 


Fuel  Value  of  Food. 

The  different  classes  of  food  compounds  or  nutrients  in  a  feed,  in 
addition  to  their  special  functions  of  forming  protein  and  fat,  yield 
energy  in  the  form  of  heat  and  muscular  strength.  The  fuel  or 
heat  value  of  these  nutrients  has  been  measured  and  is  expressed  in 
calories. 

A  calorie  is  the  amount  of  heat  necessary  to  raise  the  temperature 
of  a  pound  of  water  four  degrees  Fahrenheit.  The  calories  in  each 
of  the  three  classes  of  nutrients  are,  on  the  average  :  — 

CALORIES. 

In  one  pound  of  protein 1,800 

In  one  pound  of  fats 4.'_"J0 

In  one  pound  of  carbohydrates 1,800 

The  calories  in  a  pound  of  fats  are  equal  to  those  in  about  two  and 
one-quarter  pounds  of  protein  or  carbohydrates.  In  calculating  the 
nutritive  ratio  of  a  ration,  the  fats  are  multiplied  by  two  and  one- 
quarter,  in  order  to  convert  them  into  terms  of  carbohydrates.  The 
digestible  nutrients  in  the  standard  ration  for  milch  cows  contain 
29,000  calories. 


206 


APPENDIX. 


Table  VII.    Feeding  Standards. 
POUNDS  PER  DAY  PER  1,000  POUNDS  LIVE  WEIGHT. 


o 

- 
to 

u 

O 

>> 

•3  •« 

o<^ 
H 

Digestible 
Nutrients. 

A 

s 

CO 
<D 

Is 
3l 

o  ® 
H 

Kind  of  Animal. 

a 

O 

u 

P4 

Is 

rfg 

o 

Is 

_6 

n 

> 

"I 

Horse,  at  light  work 

21.0 

1.5 

9.5 

0.40 

11.40 

l 

7.0 

"           average  work    

22.5 

1.8 

11.2 

0.60 

13.60 

l 

7.0 

"           hard  work 

25.5 

2.8 

13.4 

0.80 

17.00 

l 

5.5 

Oxen,  at  rest  in  stall 

17.5 

0.7 

8.0 

0.15 

8.85 

l 

12.0 

"           ordinary  work 

24.0 

1.6 

11.3 

0.30 

13.20 

l 

7.5 

•'           hard  work 

26.0 

2.4 

13.2 

0.50 

16.10 

l 

6.0 

Oxen,  fattening,  first  period    .... 

27.0 

2.5 

15.0 

0.50 

18.00 

l 

6.5 

"            "          second  period    .    .    . 

26.0 

3.0 

14.8 

0.70 

18.50 

l 

5.5 

"            "           third  period  .... 

25.0 

2.7 

14.8 

0.60 

18.10 

l 

6.0 

Milch  Cows .    .    .    . 

24.0 

2.5 

12.5 

0.40 

15.40 

i 

5.4 

Sheep,  wool-producing  (coarser  brec  ds) 

20.0 

1.2 

10.3 

0.20 

11.70 

l 

9.0 

"                  "               (finer  breeds)   . 

22.5 

1.5 

11.4 

0.25 

13.15 

i 

8.0 

"       fattening,  first  period  .... 

26.0 

3.0 

15.2 

0.50 

18.70 

l 

5.5 

"            "            second  period  .    .    . 

25.0 
36.0 

3.5 
5.0 

14.4 

0.60 

18.50 
32.50 

l 

l 

4.5 

Swine,  fattening,  first  period  .... 

27 

.5 

5.5 

"            "            second  period  .    .    . 

31.0 

4.0 

24 

.0 

28.00 

l 

6.0 

"            "            third  period     .    .    . 

23.5 

2.7 

17 

.5 

20.20 

i 

6.5 

GROWING  CATTLE. 

Age,               Average  live  weigJU 
Months.                     per  head. 

22.0 

4.0 

13.8 

2.0 

19.8 

4.7 

3-6 300       "       .... 

23.4 

3.2 

13.5 

1.0 

17.7 

5.0 

24.0 

2.5 

13.5 

0.6 

16.6 

6.0 

24.0 

2.0 

13.0 

0.4 

15.4 

7.0 

18-24 850        "        .... 

24.0 

1.6 

12.0 

0.3 

13.9 

8.0 

APPENDI r 


207 


Table  VIII.    Fertilizer  Constituents  in  Fodders  and  Feeds. 

v 


Kind  of  FKKDrsa  Stuff. 


Pounds  per  Ton. 


Corn  Fodder  

Corn  Stalks 

Timothy  Hay 

Red  Clover  Hay  .... 
Scarlet  Clover  Hay  .  .  . 
Alsike  Clover  Hay       .    .    . 

Wheat  Straw 

Rye  Straw 

Oat  Straw 

Corn  Kernels,  Flint  .  .  . 
Corn  Kernels,  Dent    .    .    . 

Winter  Wheat 

Rye 

Oats .    . 

Buckwheat 

Wheat  Bran 

Wheat  Middlings    .... 

Rye  Bran 

Corn  Bran      ...... 

Buck  a  heat  Brau    .... 

Buckwheat  Middlings     .    . 

Malt  Sprouts 

Breweri*'  (trains  .... 
Brewers' Grains,  Dried  .    . 

(Jin' en  Meal 

Chi   :ip>  Gluten  Meal.     .     . 

Gluten  Feci  .    .    . 

u  Feed 

Hominy  Crop 

Corn  OH  Meal 

Ctttonseed  Meal      .... 

I -in  seed  Meal  (old  [>r iss) 

Linseed  Meal  (new  process) 


14. 
14. 
18, 
39 
55, 
41 
10 
9 
12 
33 
33 
37, 
34, 
37 
32, 
49. 
50, 
4G. 
3G. 
70. 
89, 
82, 
18, 
V'J 
105 
110, 
68 
33 
36. 
7!) 
136, 
107 
108, 


6.8 

4.6 

6.6 

7.2 

13.9 

13.4 

1.8 

5.8 

4.4 

14.0 

14.0 

18.6 

17.0 

17.8 

9.0 

57.8 

28.2 

32.0 

3.8 

34.0 

44.2 

32.6 

6.2 

21.8 

11.2 

5.8 

7.6 

25.0 

29.8 

29.0 

61.6 

38.6 

35.6 


11.2 

19.8 

28.4 

42.0 

44.2 

44.6 

14.4 

15.8 

24.2 

8.0 

8.0 

12.8 

11.2 

13.4 

4.2 

32.2 

14.0 

19.2 

1.4 

22.8 

23.0 

37.0 

1.0 

1.6 

1.4 

1.0 

1.4 

13.4 

14.6 

3.4 

38.0 

28.2 

•>7  <) 


INDEX. 


Aberdeen  Angus  cattle,  179. 
Air,  food  derived  from,  10,  12. 
Albuminoids,  139, 140. 
Ammonia,  definition  of,  69;  sulphate 

of,  uses  and  composition,  72. 
Analysis  of  soils,  value  of,  31. 
Animal  body,  ash  constituents  of,  140 ; 

composition  of,  137 ;  functions  of, 

144  ;  nitrogenous  constituents  of, 

139. 
Animal  bone,  80. 
Animal  charcoal,  84. 
Animal  food,  chemical   analysis   of, 

143 ;  classes  of,  140. 
Apatite,  87. 
Ash,  determination  of,  in  feeds,  144 ; 

of  animal  body,  140. 
Assimilation,  12. 
Atavism  in  breeding,  171. 
Atmosphere,  action  of,  on  soils,  20; 

as  source  of  food,  12. 
Ayrshire  cattle,  178. 
Azotine,  75. 

Bacteria,  effect  of,  on  milk,  188. 

Basic  slag,  88. 

Beet  family,  128. 

Blood,  dried,  74. 

Bone,    composition    of    animal,    81  ; 

boiled,  82 ;  fineness  of,  82  ;  raw,  82 ; 

steamed,  82. 
Bone  ash,  85. 

Bone  black,  84  ;  superphosphate,  91. 
Bran,  as  a  feed,  150. 
Breathing,  functions  of,  145. 
Breed, influence  of, on  milk,  184 ;  value 

of  pure,  174. 
Breeding,  as  a  business,  174 ;  atavism 

in,  171 ;  cross,  173, 175 ;  heredity  In, 

170 ;  in-and-in,  173  ;  lineage  in,  172  ; 

prepotency  in,  172 ;  principles  of, 

170 ;  variation  in,  171. 


Brewers'  grains,  as  a  feed,  150. 

Buckwheat,  as  catch  crop,  46. 

Butter,  color  of,  193;  composition  of, 
191 ;  flavor  of,  192  ;  keeping  qual- 
ity of,  192  ;  sweet-cream,  193;  tex- 
ture of,  192  ;  yield  of,  191. 

Butter-fat,  composition  of,  182. 

Buttermilk,  composition  of,  195. 

Canadian  apatite,  87. 
Capillary  attraction,  49. 
Carbohydrates,  composition    of,   141 ; 

determination  of,  144. 
Carrot  family,  128. 
Castor  pomace,  78. 
Catch  crops,  46. 
Cattle,  breeds  of,  beef,  179;  butter, 

177 ;  milk,  177. 
Cellulose,  144. 
Cereals,  description  of,  129 ;  as  feeds, 

149. 
Charcoal,  animal,  84. 
Cheese,  composition  of,  193 ;  as  food, 

194  ;  manufacture  of,  193. 
Clay,  composition  and  properties  of,  24. 
Clay  soils,  26. 
Claying  of  soils,  44. 
Climate,  effect  of,  37. 
Clovers,  description  of,  127, 132. 
Colostrum,  186. 
Commercial  values,  106. 
Composts,  59. 
Cotswold  sheep,  180. 
Cottonseed    meal,    as   feed,*  162;    as 

manure,  77. 
Cow  manure,  54. 
Cream,  composition  of,  189. 
Creaming,  by  centrifugal  force,  190; 

by  setting,  190. 
Crops,  demand  for  special,  113. 
Crude  fibre,  determination  of,  144. 
Cultivating,  60. 


209 


210 


INDEX. 


Dairy  cattle,  breeds  of,  177. 
Dairying,  elements  of  success  in,  195, 

196, 197. 
Diffusion,  13. 
Digestibility  of  feeds,  154. 
Digestion    coefficients,  155 ;  function 

of,  145. 
Drainage,  function  of,  42 ;  methods  of, 

43. 
Dried  blood,  74. 
Dried  fish,  76. 
Dried  meat,  75. 

Earth  worms,  effect  on  soils  of,  22. 
Egg-plants,  127.  * 

Ensilage,  149. 
Excretion,  functions  of,  146. 

Fallow,  bare,  116 ;  cropping,  116. 

Farming,  extensive,  120;  intensive,  120. 

Farmyard  manure,  53. 

Fat,  in  animal  food,  141  ;  determina- 
tion of,  143. 

Feed,  definition  of,  146;  digestibility 
of,  154 ;  gluten,  151 ;  manurial  value 
of,  166,  168;  mill,  150, 166. 

Feeding,  economy  in,  164, 165 ;  fertility 
in,  166;  objects  of,  157. 

Feeding  standards,  158 ;  use  of,  159. 

Felt  waste,  61. 

Fermentation  of  manures,  57. 

Ferments,  effect  of,  on  milk,  188. 

Fertility  of  soils,30;  true  measure  of  ,34. 

Fertilizers,  advantages  of  different, 
103;  analysis  of,  108;  complete, 
102;  formulas,  108;  incomplete, 
102;  methods  of  buying,  102; 
special,  110 ;  use  of,  110. 

Fertilizing  elements,  essential,  52. 

Fertilizing  materials,  classes  of,  68; 
standard,  100. 

Fish,  dried,  76. 

Florida  phosphate,  86. 

Fodder,  definition  of,  146;  green,  149. 

Food,  classes  of  animal,  140  ;  definition 
of,  146. 

Fruit  crops,  135 ;  manures  for,  136 ; 
soils  adapted  to,  136. 

Galloway  cattle,  179. 
Gas  lime,  65. 
Gelatinoids,  139. 


Germination,  15 ;  conditions  necessary 
for,  16. 

Gluten  feeds,  151. 

Grades,  breeding  of,  173. 

Grasses,  description  of,  126, 131. 

Green  manuring.    See  Manures. 

Guanos,  phosphatic,  88. 

Guaranteed  composition,  104;  inter- 
pretation of,  104. 

Guernsey  cattle,  177. 

Gypsum,  66. 

Hair  waste,  61. 
Harrowing,  50. 
Hay,  cutting  of,  best  time  for,  147 ;  as 

a  feed,  147. 
Heredity  in  breeding,  i7fl.     r 
Hereford  cattle,  179. 
Holstein-Friesian  cattle,  178. 
Hominy  meal,  as  a  feed,  152. 
Hoof  meal,  77. 
Horn  meal,  77. 
Horned  Dorset  sheep,  180. 
Horny  matter  in  animal  body,  139. 
Horse  manure,  54. 
Horses,  breeds  of;  American  trotting, 

176;    draft,   175;    heavy  carriage, 

176 ;   saddle,  176 ;    thorough-bred, 

176. 
Humus,  composition  and  effect  of,  25. 

Iron  phosphate,  88. 
Irrigation,  43. 

Jersey  cattle,  177. 

Kainit,  composition  of,  97 ;  use  of,  as 
manure,  97. 

Lactation,  period  of,  186. 

Land  plaster,  66. 

Leaf,  structure  of  the,  12. 

Leather  meal,  61,  77. 

Legumes,  127. 

Leicester  sheep,  180. 

Lime,  effect  of,  24,  47,  51,  64,  67 ;  gas, 

65 ;  shell,  65 ;  slaked,  65. 
Limestone,  65. 
Limestone  soils,  27. 
Lincoln  sheep,  180. 
Lineage  in  breeding,  172. 
Linseed  meal,  as  feed,  152. 
Loamy  soils,  27. 


INDEX. 


211 


Magnesia,  sulphate  of  potash  and, 
99. 

Manure,  agricultural  value  of,  71 ;  ar- 
tificial, 68 ;  care  of,  56 ;  commercial 
value  of,  106 ;  cow,  54 ;  definition 
of,  52;  farmyard,  53;  application 
of,  58  ;  for  fruit  crops,  136  ;  green, 
44,  47 ;  crops  useful  as,  44 ;  care  in 
use  of,  46 ;  horse,  54  ;  improvement 
of,  57  ;  loss  in,  55  ;  natural,  53  ;  ni- 
trogenous, 69,  111 ;  phosphatic,  80, 
111 ;  pig,  54  ;  potassic,  95,  111 ;  poul- 
try, 58  ;  preservers  of,  66  ;  sheep, 
54 ;  stable,  composition  of,  54 ;  use 
of,  111,  112. 

Market  garden  crops,  135. 

Marl,  use  and  composition  of,  44,  63. 

Meat,  dried,  75. 

Melon  family,  128. 

Merino  sheep,  179. 

Middlings,  as  feed,  150. 

Milk,  changes  in,  188  ;  composition  of, 
182,  183,  185 ;  effect  of  bacteria  on, 
188;  Influence  of  food  on,  187; 
properties  of,  182 ;  variations  due 
to  time  of  drawing,  186 ;  yield  of, 
from  different  breeds,  185. 

Muck,  use  of,  59,  60. 

Muriate  of  potash,  98. 

Nitrate  of  potash,  composition  of,  72. 
Nitrate  of  soda,  composition  of,  71. 
Nitrates,  application  of,  79 ;  use  of,  69. 
Nitrification  in  soils,  40. 
Nitrogen,  forms  of,  69 ;  as  manure,  69, 

78  ;  organic,  definition  of,  69 ;  uses 

of,  73,  79. 
Nutritive  ratio,  160. 

Oyster  shells,  65. 

Palatability  of  rations,  162. 

Peanut  meal,  as  feed,  153. 

Peat,  use  of,  59,  60. 

Peaty  soils,  27. 

Pedigree,  173. 

Phosphates,  animal,  80;  composition 
of,  90;  definition  of,  80;  fixation 
of,  94;  Florida,  86;  Insolubility  of, 
89  ;  iron,  88 ;  mineral,  85  ;  odorless, 
88  ;  South  Carolina,  86. 

Phosphatic  guanos,  88. 


Phosphoric  acid,  insoluble,  89;  in 
soils,  29 ;  soluble,  91,  93. 

Pig  manure,  54. 

Plant-food,  sources  of,  10. 

Plant-food  constituents,  9,  11 ;  deter- 
mination of,  11;  functions  of,  15; 
supply  of,  14. 

Plants,  agricultural  classification  of, 
128 ;  air-dry,  8  ;  annual,  16 ;  bien- 
nial, 16;  botanical  classification 
of,  126 ;  development  of,  17 ;  dry 
matter  of,  8 ;  life  of,  duration  of, 
16;  parts  of,  7;  perennial,  17; 
water  in,  7. 

Plaster,  land,  66 ;  New  York,  67 ;  Nova 
Scotia,  66. 

Plowing,  fall,  48 ;  methods  of,  48  ;  sub- 
soil, 48. 

Pony  breeds,  176. 

Potash,  double  sulphate  of,  and  mag- 
nesia, 99 ;  muriate  of,  98 ;  nitrate 
of,  72;  in  soils,  30;  sulphate  of, 
98. 

Potash  manures,  95 ;  forms  of,  96. 

Potash  salts,  appearance  of,  99 ;  uses 
Of,  99. 

Potatoes,  sweet,  127 ;  white,  127. 

Poultry  manure,  58. 

Prepotency  in  breeding,  172. 

Protein,  determination  of,  143. 

Quick-lime,  65. 

Rations,  balanced,  164  ;  examples  of 
good,  163 ;  preparation  of,  161 ; 
wide  vs.  narrow,  161. 

Respiration,  functions  of,  145. 

Reversion  in  breeding,  171. 

Rice  bran,  as  feed,  153. 

Rolling,  50. 

Root  crops,  133. 

Roots,  structure  of,  13 ;  functions  of, 
13. 

Rotations,  advantages  of,  114;  in 
dairy  farms,  120 ;  examples  of 
good,  117,  118;  for  hay  crops,  120; 
in  market  gardening,  120. 

Roso  family,  128. 

Rye,  as  catch  crop,  46. 

Salt,  use  of,  67. 
Saltpetre,  72. 


212 


INDEX. 


Sand,  composition  and  properties  of, 
23. 

Sandy  soils,  26. 

Seed,  adulteration  of,  123 ;  change  of, 
124 ;  germinating  power  of,  125 ; 
what  is  good,  122;  impurities  in, 
122;  quality  of,  123;  selection  of, 
122;  testing  of ,  125. 

Sheep,  breeds  of,  179. 

Sheep  manure,  54. 

Shorthorn  cattle,  178. 

Skim-milk,  composition  of,  194;  as  a 
food,  195. 

Soils,  absorptive  properties  of,  38 ;  al- 
luvial, 23  ;  analysis  of,  31 ;  changes 
in,  37  ;  classification  of,  23 ;  chem- 
ical composition  of,  31 ;  chemical 
improvement  of,  50  ;  clay,  26;  clay- 
ing of,  44 ;  constituents  of,  33 ; 
definition  of,  18 ;  drift,  23  ;  effect 
of  atmosphere  on,  20;  effect  of 
lime  on,  24,  47,  51,  64,  67;'  effect 
of  growth  of  plants  on,  21 ;  effect 
of  water  on,  20  ;  exhaustion  of,  35  ; 
natural  fertility  of,  30;  food  ob- 
tained from,  13 ;  formation  of,  20 ; 
imperfections  of,  41 ;  improvement 
of,  41, 50;  inorganic  substances  in, 
29  ;  limestone,  27  ;  loamy,  27  ;  mar- 
ling of ,  44  ;  movement  of,  22 ;  nitri- 
fication in,  40  ;  organic  substances 
in,  29 ;  origin  of,  18 ;  peaty,  27 ; 
perfect,  27 ;  preparation  of,  50 ; 
sandy,  26 ;  sedentary,  22 ;  natural 
strength  of,  35 ;  texture  of,  36 ; 
transported,  23;  vegetable,  27; 
weight  of,  31. 


South  Carolina  rock,  86;  superphos- 
phate, 91. 

Southdown  sheep,  180. 

Stable  manure,  composition  of,  54. 

Stalks,  as  feed,  148. 

Straw,  as  feed,  148. 

Subsoil,  definition  of,  19  ;  function  of, 
20. 

Sulphate,  of  ammonia,  72 ;  of  potash, 
98 ;  of  potash  and  magnesia,  99. 

Superphosphates,  composition  of,  92 ; 
definition  of,  90  ;  use  of,  95. 

Swine,  breeds  of,  180. 

Sylvinit,  composition  of,  97 ;  use  of, 
as  manure,  97. 

Tankage,  75. 

Thomas  phosphate  meal,  88. 

Tillage,  47. 

Tomatoes,  127. 

Tuber  crops,  134;  as  food,  149. 

Turnip  family,  127. 

Unit  System,  106. 

Values,  commercial,  106. 
Vegetable  soils,  27. 

"Wastes,  utilization  of,  61. 

Water,  action  of,  on  soils,  20. 

Wheat  plant,  composition  of,  32. 

Wheat  soil,  composition  of,  32. 

Whey,  195. 

Wolff's  feeding  standards,  158. 

Wood  ashes,  use  and  composition  of, 

62. 
Wool  waste,  61. 


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